I don't mean to scare you with anything I am about to tell you, I am trying to be honest.
I spent over five years in high school, though I graduated at my fourth year. I stayed for at least an extra, picking up some extra courses to throw on my record.
I have been to over seven different high schools because of rather frequent moving, due to various circumstances which don't seem important enough to mention.
At each high school, there was the same social formula. Everyone was part of a clique, or they had their own set of mix and match friends (meaning friends who may not have had similar interests, but they were good enough to hang out with). Most socializing was done within each clique, unless work groups were chosen by the instructor.
Those work groups were a nightmare. I would always get stuck with a group of students who didn't want to do any work, and I would shoulder their work just so that I could ensure a good mark for myself. Yes, sometimes group marks affect individual marks -it is incredibly unfair.
I don't know whether or not you are able to select your own courses, but around eleventh grade was where I found the most freedom.
I was able to pick which courses I wanted to take, and I finally got to work with people who had similar interests -regardless of whoever was in my group. It made the projects much better because everyone wanted to do their share of the work.
Socially, I would advise you to avoid falling into a clique. A group mentality among friends is one thing, but amongst a clique, it is not worth the aggravation. If you want to stick to maintaining your grades and developing as a person -not necessarily maturing- find a few people and start a group of friends who you can joke around with. Remember: it is important to have friends, not sheep. People who have worked to get into cliques get nothing out of it other than bad habits, and loathing from every other student who isn't a part of their clique.
Do your own thing, go with the flow, stay focused, get your work done -and above all else...
DO NOT QUIT. Strive to graduate, and aim for high marks. If anyone puts you down, imagine where they will be in a few years. Even privileged people who aren't self-sufficient wont get anywhere without a diploma. Keep your chin up in your academics, relax with your friends, and try to keep up with everything else.
By the way, lockers are not all they are cracked up to be. I never used mine, because there was always some moron breaking into them and stealing from other students.