To make a copy of  pre-existing content items on a Moodle page:

1.  On your course page go to the top right and click on Edit mode to turn editing on.
Course page top right corner with 'Edit mode' highlighted to be toggled on
2. Find the content you would like to make a copy of and go to the ellipsis ('...') icon tab to the top right of the item.
3. From the dropdown select Duplicate.
Activity 'Unit 2 Discussion forum' displaying with elipsis pressed on its right corner with duplicate option highlighted

This will create your copy below the original course item, with the annotated title (copy)

Duplicated version displaying signified by 'Unit 2 Discussion Forum (copy)'
4. From here you can edit the copy as needed in the Edit tab, Edit settings.
Elipsis pressed on 'Unit 2 Discussion Forum (copy) with 'edit settings' option highlighted'
This will take you to the edit page.

5. In the Edit page, update your duplicate file to make any relevant changes.
'Edit Settings' menu open with description section highlighted and 'save and return to course' option highlighted at the bottom6. Once complete, click on Save and return to course or Save and display to see your completed item.
Save and return to course and Save and display buttons

You can find information more on the reusing activities in Moodle