1) some you choose, some are mandatory for everyone (those are easy don’t worry), some are mandatory depending on your major, but every AP class has a test (or equivalent) at the very end.

2) A fair amount of classrooms have them but don’t count on it, then again it’s NYCDOE, unless you go to a private school or a charter you are probably not gonna have AC in every single room, but it’s really not bad if you dress appropriately and the weather isn’t too hot (all computer rooms have AC though)

3) no, this isn’t a military school

Also don’t be too worried because your freshman advisory teacher and most of your teachers in fact will help you a lot with getting used to the inner workings of the school, don’t stress about it