Hi, Janice.
First, go to Site Administration>>Appearance>>Navigation and make sure the "Show all courses" tick box is unchecked on your site. If it is ticked, turn it off. If it is already off, you might be running into an issue that happens only for users who are not enrolled in three or more courses. Users who are enrolled either as teachers or enrolled as learners in at least three courses will stop seeing that link if that box is unchecked.
How did I handle it in those situations? On sites where most of my incoming users were enrolled in only one or two courses, that link would still show up for me unless I made the decision that only 1 (maybe 2) courses would be accessible on the main landing page--or unless I enrolled everyone in a "Commons area" course that had simple orientation materials or organizational marketing docs and general resources in it. This course then pushed their total enrollments higher for the purposes of Moodle turning off that link for me, whether they ever went into the commons area or not.
Other options: If you make the dashboard the default landing page, users with low course enrollments aren't as likely to see that link.
Hope those suggestions are helpful. Best,
Lesli