First, our world is so focused on things that lead to problems and unforeseen consequences that aren't worth the price we pay. Peer pressure might seem like an elementary concept and you might feel like you are above temptation from friends and peers but nobody is. Please know that anyone who makes you do something you know is wrong is not a true friend and your "friendship" needs evaluating.
Secondly, in a world obsessed with image and status, it can be tempting to want to look like a certain singer, actor and emulate them in the way you dress and do your makeup. There is nothing wrong with having a look inspired by a celebrity but make sure you don't start sizing yourself up to them. You are a perfect individual created by God and made in his image and you don't need to look like anyone but yourself to impress him.
This can also go the other way and you can start comparing other people to yourself. You can start thinking you are better then others because you have better hair, clothes or are thinner. You could also start labeling people as "bad" because of decisions that they make in their lives. No one deserves a label, we as humans have no right to give people labels because we have not lived out the same situations they have.
Remember that you are beautiful and God has a divine purpose for you life!