Sensei LMS is a free plugin that is used in some of the theme demos. This plugin allows you to create courses, lessons and quizzes.
Installing Sensei LMS
If you import a demo that uses Sensei LMS, this plugin will automatically be installed and activated. To install and activate it manually go to Aardvark > Theme Setup and under the Plugins tab find Sensei LMS click Install/Activate Plugin.
Setting Up Sensei LMS
To set up and use Sensei LMS click here.
Sensei used to be a premium plugin that included the ability to sell courses with WooCommerce. However now Sensei is a free plugin (Sensei LMS) and no longer allows you to sell courses. You now need to purchase WooCommerce Paid Courses plugin to sell courses as explained here.