You can import the content of an old course into a new one.
Create a new, blank course and from within the blank course, select import like is shown below. If you're unsure how to create a new course, check out the instructions here before you begin these instructions.
You'll see a list of courses in which you are the teacher in Moodle. Search for and select the prior semester course from which you'd like to import or copy the contents.
It'll ask if you want to import the entire course under import setting. If you do wish to import all the contents of the prior course (enrollees and their data will never be imported), just click 'jump to final step'.
On the next screen, you'll be given the option to start the import. Go ahead and click the import button to continue. After a brief loading screen, you'll be notified that your import is complete.