If you have a course with a lot of users enrolled, you might like to consider setting up groups within the course. You could do this to designate class groupings, levels or other groupings according to your needs.
There can be a lot of benefits of having groups within the course; key among them to my thinking are (1) the capacity to monitor and check grades by group rather than entire cohort, (2) allocating specific tasks or content to particular groups (facilitating customisation), and (3) setting up collaborative tasks or projects to be handled in designated groups.
Here are the basics involved in sorting your enrolled users into specific groups in Moodle:
In a follow up tutorial I'll be demonstrating how to quickly check grades and activity by group rather than whole cohort, and other practical uses for group settings will be added in due course.
You can see all of my Moodle tutorials at the central resource page here.