Admin can easily manage the multiple layouts for the single course page from the backend as Reign LearnDash addon provides you to set different layouts for the single course page.
Go to Dashboard >Reign Settings >LearnDash > General, here you can see “
If you want to set layout for any individual courses. Then go to Dashboard >LearnDash LMS > Courses .
Select any course and click on edit. Now you can set the course layout from here and don’t forget to click on update button.