Being 12 is sort of the last of the years where you can still enjoy your 'freedom' as it were. Don't spend it all online, get on your bikes, enjoy the outside world. That's what people my age did when we were twelve.
I'm 24 now and I've got my career on the go, bills to pay, rent, no real money to spend on the things that I would really want to spend my hard earned money on. My job can earn me 50k a year but even on that you would still have to budget and monitor finances closely like I do now earning almost half that a year. Life starts to really suck at about nineteen. Enjoy it while you can.