How to add a Buy button to course - the set page layout doesnt flow logically

I seem to be missing the way the CoursePress theme works - once you have created a Course, and it displays on the Courses page, you then click the DETAILS button to see the detailed info on the course. That page then displays the course info, price, 'about the course', course structure with units, but then there should be a BUY button or JOIN this Course button so that the potential student can take it further..it just ends there. This doesn't seem logical that it ends there with the student wondering how to sign up for that course. The only place I see a BUY button is on the products page...how do I get one on the Course Details Page?