Please follw this instructions. This helped me sign in without entering a credit card
Credits to mountaingoatgirlDec 29, 2013 3:22 PM Re: Can't download apps without credit card.
Re: Can't download apps without credit card.in response to Ramiro14
I spoke with Apple Tech Support and they guided me through this. I was trying to get the App Store working on a new iPad mini using a new, but existing Apple ID. To get it to work, I had to go onto iTunes on my main computer (not on the iPad). I had been trying to use the Sign In button, and I was having the issue of being "forced" to enter a credit card, which I did not want to do. Here was the solution I was given, which worked for me.
- Log out of iTunes, if you are not already. (Or hit Cancel if you're on the Review Payment screen.)
- Instead of going into Sign In, go to Redeem under the Quick Links, on the right-hand side, down a bit.
- Go through the screens, accepting the EULA, etc. You will get to a Review Payment screen, similar to the one you saw before, but it will have a None button.
- You can enter an iTunes card here if you want, but I was able to leave that field blank and still successfully get the account set up, ready to use on the iPad.