This Apple ID has not yet been used in the iTunes Store. message
I'm an android user, but just bought an iPhone. I was going to sign up with Mint Mobile, so I was going to download the Mint app to activate the trial account. Everything was going fine, and my phone said it was installed. But then it told me that "This Apple ID has not yet been used in the iTunes Store." I tried to do that by tapping Review, and was told that I had to enter my Apple ID and password. But it only seemed to want the password. But when I enter the password, I'm just cycled back to it saying "This Apple ID has not..." again. And no download.
I suppose it's some newbie mistake of some sort, but I can't figure it out. Any help?