itch.io

sorry if you've already heard this but training first then everything else second is just the easy way to avoid any dead end that requires you to have trained a certain amount of times.

apart from that doing first deryl's/cheerleader stuff when you cant train its the optimal if you want to access an extra option to get an alternative path during a scene (party scene) (doesnt matter much either, just cool)

apart from those things the variations are very small to nonexistent on what you do first and at one point the game straight up tells you that from this point on it will loop the days before a big event (mall) and you can just play all the rest of the stuff that you havent done yet before proceeding to said event

if you still just wanna do something else anyway you can just alternate: train once, do something else, repeat.
pretty sure that should work. alternatively there is the walkthrough but that's more likely to spoil the game rather than help you enjoy the start (after the mall is done you always have time to do everything)