hi, the code has rubbed off when scratching the label off

For the gift card code, if this page doesn't help then you will need to try contacting iTunes Support (you will probably need to give them images of the front and back of the card, and possibly its receipt) : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then iTunes Cards And Codes

For the security questions, if you have a rescue email address (which is not the same thing as an alternate email address) set up on your account then go to https://appleid.apple.com/ and click 'Manage your Apple ID' on the right-hand side of that page and log into your account. Then click on 'Password and Security' on the left-hand side of that page and on the right-hand side you should see an option to send security question reset info to your rescue email address.

If you don't have a rescue email address (you won't be able to add one until you can answer 2 of your questions) then you won't get the reset option - you will need to contact iTunes Support or Apple to get them reset.

e.g. you can try contacting iTunes Support : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then Account Management , and then 'Forgotten Apple ID security questions'

or try ringing Apple in your country and ask to talk to the Accounts Security Team : http://support.apple.com/kb/HE57

When they've been reset (and if you don't already have a rescue email address) you can then use the steps half-way down this page to add a rescue email address for potential future use : http://support.apple.com/kb/HT5312 . Or, if it's available in your country, you could change to 2-step verification : http://support.apple.com/kb/HT5570