Ok, twerp poet iTunes support couldn't help me and Johanna it looks like that but the id is there but greyed out however.
My App Store works! I have no idea why but I tapped it and it loaded, safari works fine, not that that's a problem because I use Chrome and so does the iTunes Store. The last thing I did was erase and reset. A day later it works.
I'm glad your problem is solved, and thank you for telling us what you did. It might help someone else who's in the same boat.
A question, out of curiosity: when you scroll down in App Store - Featured: does it show your Apple ID? Is it greyed out as well, just like in Settings? (Well, actually two questions, obviously. )
I'm glad it's working for you now. And, yes, sometimes things fix themselves for no apparent reason, just like they broke for no apparent reason. That's computers.
Sorry iTunes Support didn't' help, but since they are free it doesn't hurt to ask them. Well, not much. And they have helped me in the past, so I'm inclined to think of them kindly.