High school advice?

Every school is different in terms of what the upperclassmen are like, so im sure i cant help you there. Just dont act like a douche and you should be mostly fine. but, Im gonna be a senior this year and I gotta tell ya, if you plan on going to college, you better not slack off. I regret my freshman/sophomore grades so much. If you look good to colleges, you get more free money.
Homework definitely helps. some points are better than none, so even if you do awful, there isnt a zero going down in the gradebook. so do all your assignments, even if some are half-assed.

And also, a huge thing you need to keep in mind is to try as many different things as you can. junior year was too late to try everything i decided i wanted to. no building a house or spanish 2 for me, now, unfortunately. Im not sure what im gonna go to college for is what i want to or will be able to do for the rest of my life, so theres that.

what is also nice, is making friends with the teachers. they deal with a lot of shit from every other high school student, so if they like you at least a little bit, they wont be rude to you and it'll be that much easier. also dont be on a phone or ipad or whatever nonstop when the teacher is trying to tell you things cuz then it makes it harder for you.
things can pile up on you fast, so its good to get all the things off your back that you're able to. If you need a day to take a break, then you'll have things caught up for yourself and the teachers will be nice about it.

if you're wondering anything else, just ask!