You can delete a course that you created if and only if there are no students registered for the course. This is to ensure no accidental loss of student data.
If you make a mistake during the course building process and have not yet distributed the Course Key, you can delete the course and start again. (Deleting a course frees the associated Course Key for reuse).
After selecting the course to delete, you are shown key information about the course to ensure that the correct course was selected. Roster counts, title, Course Key, start and end dates, and even access to view the syllabus are present. A special string must be entered into a text field on this page in order to confirm deletion. Any records (grades, etc.) are lost when a course is deleted.