As explained on the "Lessons and Sections" tutorial - the Worldclass online course is structured out of lessons and 2 potential section types: Pages and Tests.
Each of these elements, can be renamed, deleted and duplicated. Pages, can also be copied to different courses within your academy.
To do this, all you need to do is search for the 3 dots on the left menu next to the lesson\page\chapter name and a menu will appear allowing you to complete your desired function.
**Please note: the "Duplicate" function is enabled to pages only. This means you won't see a "Duplicate" command on the 3 dots next to the "Lesson" title, but only when clicking on the 3 dots next to a page.
You can see what this means on this very short video: