Each class has an item on each course’s settings page that controls course visibility to students. To modify this setting, click on the “Settings” link at the top of your course.
In the “General” area of the settings page is an option labelled “Course visibility” with the choice to Show or Hide. To make your course visible to students in the course list, make sure this option is set to Show.
Click Save and Display at the bottom of the page.
By default, your course should be visible to students. However, if you see that your course is set to “Hide.”, your students will not be able to access it. (or even see it in their Moodle accounts!)