I'm not a gril , but I have some tips, though I'd recommend based on my personal experience.
First of all, high school is a place where everybody judges everyone , may it be because of looks or character, grades or the clique you're in or because of whatever. What I'm saying here is that you should wear clothes of good quality, brand clothes if possible - but do not wear anything "weird" like band shirts all the time or anything really unusual. ( Always stick to the rules of your school's dress code, too, you don't want to get in trouble either) And you don't want to be the target of gossip or bullying in high school just because you wear strange clothes, you know? So, simply wear regular apparel that suits you.
Look lovie, what you wear is all based on what you want. If you like band tees wear band tees. (I wear band tees and flannels constantly. people may say some things, but let them talk. they are just jealous if they ever talk about you.) If you like to wear a tank top, wear a tank top. If you like hoodies, wear hoodies. You do you, and let the people talk. As long as it A) follows the rules B) You like it C) You think it looks good :)