Here is a simple way to import an old course to a new course.
1. Go to the new course.
2. Click the settings from the course menu.
3. Click Import Content into this Course from the tool list on the right side column.
4. Select “Copy a Canvas Course”.
5. Select the course that contains the content you want.
6. Choose all content.
7. You can adjust events and due dates.
8. Click import and wait.
More info at the following URL.