Clothes, braces and physical build to not make the person. It is your personality and the way you relate to people that is important. I'm not sure isolating yourself for half the year by doing the online school will help. I suggest you just be yourself, smile alot and start talking to people. You may be surprised that people do like you and want to be with you.

You are young. Don't worry that you are not a "ladies man". Most guys aren't. People your age are still maturing and developing their personalities and figuring out what is important to them. You should meet more people who are more in tune with themselves in the next couple of years. Give yourself time.