When I try to rent a movie thru apple tv it asks me to go to the itunes store and verify payment info. How do I do that?

you verify the appleID's payment plan

you do it in itunes on your computer or from an ios device like ipad or iphone

read more

https://www.apple.com/support/itunes/account/

Under itunes account (not on the AppleTV) go to view account. Typically it will just ask you to enter the verification code for the credit card you are using.