I mean the content of the course where student will be able to edit or change it. I think there must be another field in course table to store course content.
There is no need for course content when you've got a cname field(course name) already. Create a page course_man.php to add, edit and delete course accordingly using a html table to represent the mysql course table. Read the tut102 again and again until you understand the requested requirements.
I think I know what you mean, there is no content for courses its just names for courses, but read the tut letter again if you want to add or change the database structure you can include that in a text file not actual code.