Deleting a class can not be undone and will delete your roster, assignments, and any other data associated with the class. However, it will not delete your students' question response data.
Archiving a class is a reversible option that preserves class data while still preventing students from accessing the class.
You can delete a class by:
Clicking on the Classes tab
Selecting the class you want to delete
Clicking on the Settings tab within the class
Clicking on the Delete button as shown below.