Always train with your club, do extra bits of training on your own such as kicking practice or going to the gym doing weights and stuff. When your friends all start going out drinking and stuff, dont give into those sorts of temptations
I know I am different in your position- I am 15, a stand-off, but I have been recently taken into a district and national training sessions. The best thing you can do is to train as much as you can- Gym 3 times a week (at least) and do personal training as much as you can. Hope this helps, and good luck.