If you want to unpublish a course then this article will show you how.
Your course is now published or unpublished depending on what action you want to take with it. If it's published then new students who signup to your course will see it in their membership dashboard. If you've unpublished the course then students won't be able to see the course within their membership dashboard if they've signed up for it in the past.
If you want to unpublish a course, go the the dropdown menu on the right side of the screen and click 'Unpublish'. The status of your course will change into 'Draft'. Your students won't be able to access this course anymore.
See this article for instructions on how to publish a course.