By default, up to 12 courses show in alphabetical order on the Dashboard. You can access all courses by selecting Courses > All Courses from the Global Navigation Bar on the left side of your screen.
From the All Courses menu, you can “favorite” a course by clicking on the star next to the course name. The star will change to a gold color. Once you favorite a course, only favorited courses will show on the Dashboard. When you “favorite” a course, it essentially locks the course on your Dashboard until you “unfavorite” it. If you want to “unfavorite” a course, go to the All Courses list and click on the star to remove the gold color.
When you are enrolled in a new course, it will not automatically appear on the Dashboard. The new course will appear only in the All Courses area because you have “locked” other courses on the Dashboard. Follow the steps in the previous paragraph to update your Dashboard to show your new “favorites”.
Here is a link to more information about customizing the course list from the Canvas guides:
https://community.canvaslms.com/docs/DOC-1288
Here is a link describing the different states of a Canvas course (un-published, published, and concluded):