Family Sharing set up problems

I'm trying to set up family sharing with Apple Music and my family and I are having a difficult time.

We currently all use ONE account to make purchases on iTunes/App Store, and we each have a separate iCloud account for notes, email, etc.

I'm wondering what the best way to set up Family Sharing is, so that we can all use that same one account on iTunes/App Store while also having our own iCloud accounts linked.

Specifically, what do I put in each of these fields?

I thought that I would put my personal iCloud account in the red box and then the shared account in the blue one?

Any help would be appreciated!