Itunes. New Card?!?

I get through all the steps fine.

but STEP 3!!!!!

it says payment info! I DONT HAVE ANY INFO! I'm 13! I went to 7 eleven and bought a card today and i cant buy any songs please help me!

Okay... heres what you do.
1. Go to iTunes store.
2.click "redeem"
3.enter code
4. a window should've have popped up. Then Click redeem card
5. once you have redeemed the card, you can buy songs until the money runs out.