ipod touch 6th generation won't connect to iTunes

We have two new ipod touch 6th generations.

After working several times over 2-3 days, we did get their accounts set up connected to mine. We had several sever errors with their apple accounts.

After resettting Wifi and being as patient as possible, they are now able to use FaceTime and message.

However, the iTunes store won't connect. The App Store will connect occasionally.

What can we do to get the iTunes store to work? I want to be able to share my music with them - which we should be able to do with the family setting I put in place, right?