It's a tradeoff; I started off doing a lot of side-events, but then people get upset they miss out events. I could provide a laundry list of "go here, do that", but I personally dislike what that does to the organic exploration of the game. In the end, there's a single "core chain" of events tied to the timeline; each day progresses the story, whether or not you've done side-quests. In this I stole quite shamelessly from Persona 4/5. There's various side-quests and events, but I've shied away from 'bad' endings; I find most people just roll-back if they're aware they screwed up, or get frustrated if you don't tell them you screwed up something until 30 minutes later. So it's an affordence problem.
Anyway; the core story is unmissable, since it's on a timeline. I made the choice that no matter how you play, the core storyline would be winnable. The rest (~1/3 of the content) is optional, and based on the choices you make and the places you visit