Copying Lessons
You can find the copy button at the top right of your lesson in the editor (see screenshot):
After copying the lesson, you can go to the same shortcut area and move the lesson to a new course, or you can drag and drop the lesson to a new course if it is easier.
One note about copying to be aware of: when you copy a lesson, it will also have references to all the original attachments and media that you had for that lesson, but you will need to be careful about deleting copies of lessons. If you delete a lesson copy, it will delete the video, audio, and or download file that was uploaded to the original as well.