My iPhone 6S doesn’t recognise my Apple ID on iTunes. Help please!

Hi margery709,

Welcome to the Apple Community.

Wondering which iOS you have installed on your iPhone 6S.

Apple support have an article online that may help.

If you can't connect to the App Store, iTunes Store, or other Apple services

https://support.apple.com/en-us/HT201400

And

If you tried all of the steps in the article above, and you still can’t connect, contact Apple Support.

Hope this helps you :-)