only got android device want to set up family sharing

Ok family sharing is only supported on apple devices at the moment see this link Family Sharing - Apple.

I don’t think it will ever be used on android.

Correct. Setting up Family Sharing requires an Apple device. Once set up it can be used on Android devices.

If you don't have an Apple device, then you cannot set up Family Sharing.

That's not true, you can setup Apple Music family on Android....

Use Family Sharing with Apple Music on Android - Apple Support