Welcome to the Apple Support Communities!
If you are not able to sign in to the iTunes Store or see your music on your iOS device, try the following:
1) Make sure you have updated to iOS 11.1 on your iOS device and iTunes 12.7.1 on your computer.
2) Restart your device and your computer.
3) On your computer, open iTunes and choose File > Library > Update iCloud Music Library from the menu bar at the top of your screen.
4) On your iOS device, tap Settings > iTunes & App Store and sign in with the same Apple ID and password you used when you purchased your Apple Music membership.
5) On your iOS device, make sure iCloud Music Library is turned on.
Download iTunes 12.7.1
Update to iOS 11
Get help with iCloud Music Library
Take care.