- e-learning (this is the "my courses" page, the one you should never turn off..) => if a user is enrolled to a course, he'll see the course here
- catalogue> from what you are saying, this section is turned on
In the end: if the students can't see the courses in the "my courses" page (i.e. under the "elearning" label) it means they are not enrolled to them.
Users must be enrolled in a course to see it on the "elearning" or "classroom" tab.
If you want them to self-subscribe from the catalog, set the enrollment policy to "free" in course configuration.
Otherwise, a superadmin can subscribe users from the courses administration area, check this tutorial (it's in italian but you can easily google-translate it in your language)
I'm moving this thread in the "Administration Management" forum in english