Sharing Music & Apps with Family

A

AC Question

I just switched to Android from iOS.

I'm on a Nexus 6P and Pixel C. Just bought my 13-year-old a Nexus 5. My wife is still on her iPhone 6s Plus.

On iOS, I just sync apps and music to my boy's iPod/iPad and my wife's devices using iTunes. I can't figure out how to do that on Android.

I set up a Family Sharing plan on Google Play. In settings, on my boy's device, it shows the "Family Payment Method" or somesuch. But I don't see a way to add all my apps and music to his new Nexus. It seems FamShare is just for *new* purchases or am I doing it wrong.

I ended up adding my account to his device (and turned off syncing), so that I could add all the apps I've already paid for, but I'm not at all comfortable with all my info being a click away on his phone. There's got to be a better way. What am I missing?