To set up promoted courses for your learning portal, log in as an administrator and from your Administration dashboard go to 'Themes' (1). Within the site builder tool, for your installed theme click to Add a new Block (2).  

Type the name of the block (3) and select the "Promoted Courses" option from the Type dropdown list (4).

Fill in the required information and finally through the courses list (5) you may select among all courses in your system which ones are going to be presented as promoted.  Please note that you can add artwork to your block, using images that you have uploaded somewhere online. Just paste their URL(s) into the Artwork field (6).

Once you have created your block, click on the Insert block option (7) in order to find it (8) and insert it into the column you want (9).

After pushing your changes to the live environment, this is how the Promoted courses block will look like: