So we have a problem-parents want you to be able to take care of yourselves, and the principal says you can't fight. Sounds like we need to figure out some alternatives, at least for getting along in school. People who study human behavior have interviewed many kids your age and have found that fights seem to fall into four categories. Some kids need to be noticed a lot, and they will do things to get you to pay attention to them. If they annoy you long enough, it could lead to a fight.
Some kids like to be boss all the time.
They insist you do things their way or they won't be your friends anymore. Sometimes they try to tell you who you can or cannot hang around with. Some students fight to get even. The want revenge because they feel the other person did something to them first. Some kids feel unable to look out for themselves.