Sharing iCloud storage.
How do I keep my family from having access to my portion of the iCloud. Can they look at my pictures if we all share the same cloud?
MacBook Pro 16″, macOS 10.15
If they don't have your Apple ID and your password, they don't have access. Also see the following from Share an iCloud storage plan with your family - Apple Support
When you share a storage plan, your photos and documents stay private and everyone keeps using their own accounts with iCloud—just like when you have your own storage plan. You simply share the space available in the iCloud storage plan with your family members, so you only have one plan to manage.