Is there a "Family Plan" available?

You can share subscriptions with other family members when setting up a Family Plan. One thing to note is if you want to share a Music subscription, you would need the Family Music subscription, which does cost a little more. Here is some more info on what you may be looking for:

What is Family Sharing? - Apple Support

Here is how to: Share iCloud+ with your family - Apple Support

While iCloud+ storage is pooled among all users, each user in Family Sharing has their data and photos and such kept private, unless specific files or photos are explicitly shared by the user.