I'm going to college in September, and I want it to be a fresh start. I've also wanted to change my name for a long time. Should I change it before going to college, or wait until after I leave?
Well it depends if you want to do this in a legal sense or in just what other people want to call you because I know of both.
So if you want to do it in just the way people call you, you should just introduce yourself as your new name to other kids. You can just say that your name is one thing but then tell others that you'd like to be called another thing. A lot of kids at my university (especially kids who have names that are difficult to pronounce) do this.
I also know of this kid who wants to change his name legally but hasn't done so yet. He admits that it'll be a hassle in changing everything that he has done beforehand to be under his new name and he kinda wished he did this before college. So if you're changing it legally and want to avoid this hassle, I'd probably do it before you go to college.