On the front page of your course, you can click Import existing content > then Copy a Canvas course.
- From your course home page, choose Import existing content
- Choose Copy Canvas Course as the content type, and search for your course title from where you want to copy contents from.
- Then select All content. If you only need to copy specific parts of the course, then choose Select specific content.
- Finally, click Import.
All assignments, discussions and announcements are included in the copy, and placed under Imported assignments/discussions/announcements group. Please do remove the unneeded assignments, discussions ran/or announcments before publishing your course.
Do have a look at the full list of import behaviours and limitations.