Groups and Permissions are concepts fulfilled by Django https://docs.djangoproject.com/en/2.0/ref/contrib/auth/#django.contrib.auth.models.User.groups
New permissions can be created by defining them in Meta Class of desired model, then migrating the changes.
Groups can be created like any other object
We have a panel in the dashboard to manage staff's permission (staff management), but as I understood you want to use them for your customers?
Then you should create a custom panel somewhere in the dashboard for such purpose
is_active
can be found in django docs https://docs.djangoproject.com/en/2.0/ref/contrib/auth/#django.contrib.auth.models.User.is_active