Re: error message: This Mac can’t connect to Apple Media Services because of a problem with "my Apple ID"
You may want to check that you are signed in correctly (to your Mac) with your Apple ID:
How to: Sign in with your Apple ID - Apple Support
and
You could try logging in to your Apple ID account online, and check that all your details are correct / up-to-date.
Apple ID sign in webpage{ https://appleid.apple.com/
If needed: How to: Get a verification code and sign in with two-factor authentication - Apple Support
Also: Apple support's article about not being able to connect:
What to do: If you can't connect to the App Store, iTunes Store, or other Apple services - Apple Support
More support if needed:
Apple ID Support website (info / support / contact options etc.):
Apple ID - Official Apple Support