We've collected together some helpful strategies to help you on your quest to take over the world.
Starting your game
Most Civ players will know how to play at the start of Civ without us needing to go through things in fine detail. You'll spawn in a good spot to settle, so don't wander around (as this will set your civ back), unless there is a much better spot for your first city within a couple of tiles of your starting position. Any more and you might as well use it for your second city (which you'll want nearby anyway). On higher difficulties the other civs often start with some rather big advantages, like several extra warriors. So don't overextend and adapt your strategy to factor in that AI civs will most likely gain an advantage exploring early - get a scout out there, but don't expect to find a lot of tribal villages on higher difficulties.
Your first tech should be chosen based on the tiles around your first city. Animal husbandry is a good choice if you have cows, sheep or similar inside your city tiles. Mining if that's nearby. Pottery is a good first tech for all sorts of reasons as well, as it unlocks a key early building, the Granary, which allows for swifter growth (it also unlocks Irrigation which is an important early tech for whatever strategy you employ).
When to build your second settler is a key decision in the early game. We recommend you wait until your first city has gained at least four citizens so it will be able to make use of as many tiles and that you don't needlessly hamper its growth (your capital is key, so as you develop more cities it may be wise to build settlers elsewhere if other cities grow quickly). You can choose to be more aggressive with your expansion, but you might be a bit more vulnerable. Whether there are great spots for new cities nearby (you don't want to send settlers too far in the early game as they are easy prey for Barbarians) will also factor into this decision.
Choose your Civ carefully
While there are more options to tailor your play-style and shift things around mid-game thanks to how policies work, the first choice you make is still an important one. Each Civ has unique qualities that makes them more or less suitable for certain strategies. While you can bend any Civ to your own playstyle, particularly on the higher difficulty settings you'll want to optimise your play to the specific benefits of each Civ. Of course, many of the bonuses favour the same sort of strategy - aggression and expansion - but Rome for instance has some rather neat economic buffs that means you'll want to spread out. The bonus of getting instant roads between Rome and any new city you gain (founded by yourself or captured) means that earlier on you'll get better mobility for your army which is key if you go for an aggressive expansion where you'll likely need to fight wars on several fronts.
Arabia is a good civ to choose if you want to go for a religious win. Not only do they automatically get the last Great Prophet if they haven't already gotten one, but they also have faith and culture bonuses that will make spreading the religion a whole lot easier. The Aztec (the pre-order bonus civ) have some very particular mechanics that lend themselves to several strategies. Each luxury resource exploited gives your military units +1 attack, which is something that could prove incredibly useful if you happen to find yourself in a conflict, particularly in the early game where small bonuses make a world of difference. The Aztec also get an extra use out of Builders, and Builders can use an action to help speed the construction of a Wonder. What you should note is that these perks are not evenly balanced. Some civs will be more suitable for a certain strategy or era, and it is up to you how to best take advantage of these rather different special buildings or abilities.
Once you've understood how to best play as your chosen civ, the next step should be to try and force your opposing civs to play out of their comfort zone or for their strengths to affect you as little as possible. Knowing your enemy can be just as useful as knowing yourself. There are plenty of in-depth guides out there to get the most out of specific civs, but as a beginner you'll only need to consider the broader outlines of what objective to go for and how to take advantage of civ specific abilities, buildings or units.
Location, location, location
This applies to many things. Placing your settlements near fresh water tiles is key to growth, but this isn't the only factor you need to consider as you'll also need to be smart about cutting off access from other civs to land you may want to settle. You also need to consider that there are many district bonus and wonder requirements tied to certain tile types, which is why having some mountain tiles near a city isn't necessarily a bad thing (like it used to be). Certain civs also have bonuses tied to specific tiles (Russia gets more out of Tundra than others, while Egypt benefits more than others from placing cities along rivers). Playing as Russia it can be a viable strategy to settle along a polar region with Tundra, as other civs likely won't see it as attractive and you may end up with a favourable grasp on oil resources for the late game.
Barbarians: deal with them or deal with the consequences
Barbarians are a bit different in Civ VI and at first glance they may seem harmless. They will send out scouts from the camps that will not attack your units or pillage your tiles. However, if you leave the scout alone he'll soon come back with a proper Barbarian horde of more difficult units. Particularly in the early goings this can spell trouble. You will want to root out the problem as soon as possible and take out the camp. New camps will spawn in unclaimed territories and this is a good reason to keep a few military units around for mop up duties. You don't need to garrison your first couple of cities straight away though so you can pull those warriors/slingers/archers to deal with the first Barbarian camps you run into. Dealing with Barbarians can gain you favour with other civs, and it will also gain you healthy helpings of gold.
Use your currency wisely
Gold and faith are two currencies that you can use in many different ways in Civ VI. Having a bank can be useful, but most of the time investing your resources are advised. Having gold in case an enemy faction decides to spring a surprise declaration of war on you (this will happen a lot) is of course great, but your gold could also be spent on buying tiles for instance. Which is a great way of supercharging the growth of a recently established city (buying tiles with bonus resources, etc). It can also be a way to claim strategic tiles that connect two cities or cut off a piece of land from your opponents. Great people can also be purchased with gold or faith. This is generally not advisable as the benefits aren't huge typically, but in some cases you'll want to do this to ensure you get a certain great person ahead of another civ.
If you've got a decent bank balance and you're going for a science victory you should keep an eye on Eureka requirements; at times gold can be used to achieve these. Going for the Eureka moments is key (along with building a strong science economy) to winning the race to Mars.
Other Civs can be devious
Hidden agendas of other Civs add an interesting wrinkle to the game, but if you're doing well envy will drive most neighbouring Civs to dislike you and you'd better be prepared to safeguard your territory. If you want to play aggressively and settle near other Civs you can count on them starting to think of war. Active diplomacy can help keep things civil, but ultimately you will develop enemies as it's impossible to please all the whims of your fellow leaders. They're not always easy to read.
War is (almost) unavoidable
It's really difficult to play any Civ as a total pacifist. A strong military is a foundation you'll need, regardless of what victory condition you're aiming for. In fact, a weak military will invite aggressive AI empires to invade and try and take you out. And that's not the sort of war you'll want. However, starting wars comes with a steep warmongering penalty (unless you start a war to take back a city you once lost), so a wise strategy is to annoy neighbouring nations into attacking you first and then either raid the bank to quickly mobilise troops (this is typically a good strategy as you'll build up funds not having to pay upkeep for troops and you can also bait aggressive AI in by looking weak).
Refusing trade deals, establishing cities near the borders of another civ, or trying to spread religion can also be reasons for an enemy to attack you. And of course, some AI are just programmed to try and attack you as soon as they can anyway. If you're fairly equal in terms of tech with the nation you're entangled with, combat strategy and making sure you have terrain, experience and policy bonuses on your side is key. The AI will typically fall back with wounded units, so that's also something to keep in mind as this may give you time to switch out your frontline units or heal/upgrade them. Using ranged units to great effect is a basic, but effective strategy, and make sure that you have the proper support units on hand if you lay siege to a city. If you don't want to occupy, but merely damage an opponent there's the option of pillaging tiles, something that could handicap a city quite severely given how districts work. Later on you can also sabotage districts with spies - particularly important if one nation is attempting to complete the science victory.
City-states - the proxy war you always wanted
City-states were around in Civ V, but their role has changed here. Most importantly there is no diplomatic victory in Civ VI so a city-state's opinion of you isn't important in that regard. For those seeking military conquest, city-states can be easy target to prey on, perhaps not right at the start but after a little while. But be careful, they will be allied up and you will face retribution if you attack a city-state with ample backing from other civs. However, city-states also provide an alternative to warfare as you can fight over their favour with other civs using envoys. This clever mini-game lets you place envoys to gain bonuses from the city-states, some permanent while you will lose their top bonuses if you're not the suzerain of that city-state. A good strategy here is to try and lay claim to a couple of city-states early on and use your envoys to safeguard these. Trying to befriend every city-state will likely mean you'll lose out in some of these duels with other civs. As there is no diplomatic win you also want to make sure that the city-states you chose have bonuses that either further your winning condition directly, or alternatively shore up a deficiency.
Don't accept the first surrender
If you've managed to beat down an opposing Civ to the point where they want to surrender it may be tempting to accept it, get some gold and luxury items as compensation, and move on with your own Civ. But you should take the opportunity to press on and capture a couple of key cities from them. Not only does this further your empire, but it will weaken your enemy to the point where they likely won't recover. They'll hate you for it, but if you have a problem with that you'll be strong enough to capture the remaining cities without too much trouble.
Don't overlook religion
Your advisor (if you haven't turned her off) will typically favour you building a Holy district quite early. There is good reason for this as the race to found a religion is quite important, and not just if you're actually aiming for a religious victory. Having a religion allows for quite a few perks (pantheon allows for one, and with a religion you can have four more) that range from stuff that will give you various benefits, new buildings that provide bonuses, and things that will aid in spreading your religion. So even if you don't plan on making religion your main objective you will pass up buffs that could be crucial if you don't succeed in claiming one of the limited number of Great Prophets (who found religions) in the game.
Customise your game
There are lots of ways to enhance your Civ experience, most of them are the same as in previous games. Being able to turn off Barbarians or narrow down the victory conditions, for instance. But most important is that you can customise your map size and its layout, age and the sea level. If you want to play a game where commanding the seas is all important you may want to raise the sea level and play on a map with islands. If you don't want sea units to be a factor you can lower the sea level and play on a Pangea map. There are also more balanced options and a weird one in the shape of the inland sea that places a large sea in the middle of the map with land surrounding it. You're also allowed to set the number of civs and you can even choose what civs you'll face. This is great in case you really don't want to face a certain warmongering civ or if you want some more breathing room to expand (with fewer civs than recommended on the map).
The next obvious step are mods. There are already a bunch of useful ones out there that focus on a smoother AI difficulty, new maps, new civilisations, and new units. It may be a matter of taste as to whether they improve the game from the vanilla version, but if you've got something in particular you want to tweak, odds are there's a mod to take care of that or that there's one on the way.
These were just a few beginner's tips and some general advice on how to get the most out of Civilization VI. We recommend gently turning up the difficulty with each new game you start as you'll develop strategies and new insights each time you play a new session, evolving your strategy and bettering your odds of winning. Good luck.