You gotta fix this before you go to regular school, or you are not gonna have a good time.
First thing you have to realize is most people are idiots. This is very important. If you have too much respect for people, you wind up caring about too many people's opinions. If those opinions are negative, it is gonna cause you some misery.
However, once you realize these people are just immature and insecure, their insults will have no effect on you whatsoever.
The only people that shoud ever be able to get you down are the people you care about. Caring about the wrong people will have you very stressed out, and down a lot more often.
People are always gonna start sh*t, but you can lessen the blow by building your confidence before you get to your new school. They don't know you from Adam, so you can basically let them invent their own versions of your childhood. If you stroll in with a slouch and don't talk back, you are pretty much leaving yourself wide-open for attacks. Exposing weakness attracts the predatory mentality.
As reminded in the Free Credit Report commercial, "they say you should always dress for the job you want (not the one you have)". This is not just about clothing, it is about attitude and presence. If you come in there playing the role of a superstar, you are not gonna be treated like a ...nerd.
I once applied for a job that only had an opening for apprentice. I never intended to be an apprentice. I became the site supervisor in 2 weeks, by ignoring my title and doing what I knew how to do. I also had my pay increased 3 times in 2 years. The rewards for confidence are endless.
As for your convictions, research them better so you can duel with the most vocabulary/trivia-savvy opponent you'll find. You really need to know your facts, so you can crush an arguemnet and leave your opponent whimpering.
NEVER bend on your convictions. This is a huge, common error people make when trying to fit in. It exposes a lake of weakness large enough to pollute for decades. Your convictions are your asset and ticket to more confidence. When you are passionate and knowledgeable on a subject, you become feared by your opposition. With that fear comes respect, which adds more self-confidence.