Why I couldn't log in into an app store nor create an iTunes store account

I just created an account from my iphone 7 and I wanted to download a app, and the app store requested a log in, when I log in there is a pop up that says "this apple account has not yet been used in store." Then I tap the review, then I log in again to create an iTunes store account, after I log in it says the same thing "this apple account has not yet been used in store" over and over again please help me what's wrong with this thanks in advance.