The gym is obviously the first step.

From your post I can locate no real issue apart from perhaps a lack of confidence. If you can locate a good gym, with a trainer who will care and nurture your career, then you will find that you can develop quickly.

Age is irrelevant, if the talent is there, it's there and at 17 it will be by no means limited or reduced.

No matter what believ in yourself, remeber your ambition and work hard.

Good luck Jordan.