Was your course created for you by your administrator? You may even have gone to the Assign roles page to find that you already had students enrolled on your course. If there is no general policy for getting students enrolled on a Moodle course, then you have a number of options open to you. Let's take a look at these.

The easiest way to enroll a class onto a course is to specify an enrollment key. This is like a password for the course. Each student then tries to register on the course, and is asked for the key. They type it in and, hey presto, they are enrolled.