For the User management use this Django admin site views:
You can create users and user groups there.
You can create different kinds of Users:
Users without superuser status must have explicit user permissions to view/change/delete things.
A user must mark as staff user to go into the Django admin site. Nevertheless he must explicit explicit user permissions to view/change/delete models.
You can limit the edit and view permission for every page by set a user group for:
Use edit page -> edit all view for this. Expand the PageTree - Permissions block at the bottom of the page or change PageMeta view permission in the middle.
With limiting PageTree permission, you limit the page in all languages. Limit only PageMeta will limit the page only in this language.
Here a simple example, how to create a "protected area" on your page: Sub pages which can only see some users.
Create the viewer users, give him no permissions, add them to a group without any permissions:
Now you have users which can only login and do nothing else ;)
Now you have create a page, which can only see and view theses users from the group and all superusers.
The page would only be listed in menu, sub-menu, sitemap etc. if the user logged in. It can also only found in the search by those users.