As you already know Life is Strange 2 is a story separate from the events in the first game, as it follows brothers Sean (16) and Daniel (9) Diaz on a road trip from their home in Seattle down the coast towards Mexico where their father grew up. The background to this road trip is a traumatic event that sees their father get shot by a cop, which triggers a reaction from Daniel. A telekinetic outburst if you will, which sends the cop and all sorts of debris flying. Realising how the scene looks with a dead cop and their father dead, Sean decides to run away with Daniel who is unconscious after the blast.
It's an interesting setup to a whole new story that takes place a few years after the events in the first game. There is a bit of fan service in there for fans of the first game (no spoilers), but the game doesn't make use of your save file but rather it asks you a question about a key choice in the first game. Given how popular Chloe and Max are, it's a tall order for the brothers to keep up. The age difference is very clear at first, Sean is a moody teenager, somewhat shy and artistic, who feels his playful younger brother is cramping his style. Given what's come to pass he needs to grow up quickly in order to provide the sort of support and guidance Daniel needs as they try and survive on their own.
In many ways the first episode establishes what used to be normal for Sean and Daniel, we get to know Sean's best friend Lyla, their father Esteban, early on, before the incident. After that, it mainly focuses on the relationship between the two brothers, and for Sean, it becomes a case of bridging a gap he himself has created between him and his brother. Or not, after all, the game lets you shape the relationship with Daniel to some degree. Most importantly he will learn from your example and there are several options to be less than honest, something that could prompt Daniel to take similar actions as you're not in direct control of him.
In some ways, this makes some of the key decisions less obvious to the player, and it makes for a more organic experience in a way, even if it may come across as more linear to the player. There are key moments where you can choose between two or three options on how to proceed and these are clearly highlighted, but how you deal with Daniel has less of an immediate impact. While Max's time powers packed a bit of a punch, there's really nothing to replace that mechanic here, other than how you choose to interact with Daniel. It's quite possible something will be added to the mix later on, but in terms of mechanics, the first episode is pretty straightforward with conversation options and interactions with objects, although one neat thing is that at times you can interact with an object while talking, which then shapes the conversation.