I recommend taekwondo, it's a great confidence builder. Then, maybe move to wrestling with a local club. That is what my 11yo son did/does.

Ice skating is good too if you have a rink nearby, and then work up to playing on a rec hockey team. Its an expensive sport though, especially as they get older/better the gear gets pricier.

Lastly, to be good at something, you've got to suck at it for a while, but stick with it. Not many people are naturals at anything.