To hide a course it so it doesn’t show on your dashboard, find the course tile on your Canvas dashboard. Click the 3 dots on the upper right of the tile, then click Move > Unfavorite >Submit.
When you "unfavorite" a course it will still be available by navigating to Courses > All Courses from the main menu.
To rearrange courses on your Dashboard, click a tile and drag it to your preferred location, or click the 3 dots > Move.