From the navigation bar, find "Enrollment". Here you will manage enrollments of classes in courses, and link users to classes. The features will change depending on which view you choose at the top right corner:
On the top right corner, click on "View" next to switch view.
Here you have 2 options: Groups and users
Groups view:
Add Group - Click on "Add group" to create a new class, write its name, then click on "Add"
Edit group - Click on the pen icon to edit the group's name, then click on "Manage"
Delete group - Click on the bin icon to delete the group, then click on "Delete"
Bulk deletes - Select many groups you want to delete (or select all), click on "Delete group", then "Delete"
You can also click on a group to manage the users and courses of this group