from me, a girls point of view, I would say from experience that you should break that shell of yours, go up to a girl and just talk to her, dont be nervous but simply be yourself as confident as you are on the basketball court. If this doesn't work for you then college will. College tends to be the best time to establish your own self. Just because you're shy doesn't mean you won't get a girlfriend. Just be comfortable don't tense up, and know that even if you don't get a girlfriend now, doesn't mean you won't find the right one in the future.
I's okay; you're not doing anything wrong.
If you want some advice, then here goes. Lots of girls like getting to know you before you ask them out. Sure, some guys think that if you're friends with them, you're doomed never to date, but that's not true. All of my best relationships came after I got to know the guy. When you ask them, just be confident and be yourself, because you want a girl who likes you for you. Never change anything for a girl. There will still be some rejections, so be ready for that, but eventually, you'll meet somebody who likes you and will say yes.
hmm get over the looks part cause i mean like seriously if you walk around most places you can notice that a lot of ugly dudes with great personalities are with some of the hottest girls. I can honestly say that confidence really plays a big part in it, keep clean, good clothes, clean nice looking shoes, keep your face clean from pimples etc, all the easy things you should do do it, have confidence don’t look nervous and do what you do if you can start up a convo keep it going ask about her etc 'confidence confidence'
*honesty--> a girl has to be able to trust you
*respect--> you need to be nice to your lady,, show you care
*love--> love her with all your heart and mean it
*NEVER cheat or flirt with any other girl,, that hurts us
*you should show that you are atleast a little protective
*hold her close when shes cold
*kiss her every second she looks in your eyes and tell her she is beautiful
Good luck hope i helped :)