When you first load up the authoring tool, you'll see the dashboard; a view of every course created in the app. You can organise the view of courses using the onscreen filters and search controls to the top right of the screen.

Also notice the button to create a new course in the dashboard's sidebar.

The shared courses section will give you a list of courses others have created and shared within the system. In addition to being able to view these courses, you can also edit them (depending on your user account privileges).

To make a course you've authored yourself viewable in this section, you must enable the relevant configuration setting.