I agree with what resistance said. If they don't want to go out with you because of your looks, then maybe they need to get their priorities straight. But 7th grade, that's 12 or 13, right? I'm assuming you fit in with that age group, and if you do, there's plenty of time to find a girlfriend. You never know, maybe someone does have a crush on you and is too shy to say so. I do know that back when I was in 7th grade, I had a crush on a boy and was trying to hide it. Whenever someone asked me if I liked him, I always said no. I was too insecure to admit it, because no matter who I liked, I was afraid I'd be teased simply for saying that I liked somebody. As people grow up, I've noticed that they generally grow out of that.
Just enjoy where you're at in your life. Find something you're interested in, be it sports, art, music, shop, whatever. Get to know some people on a friend-to-friend basis, don't push, and you never know what might come of it. If love is going to happen, it'll happen in its own time. And at 12 or 13, there's plenty of time to worry about that. Good luck.