There is no single place where you edit or manage the Table of Contents (TOC) for a course. Rather this is done as you build the course.
Each course will have a TOC which includes all of the Chapters referred to as the "Course Contents". Any section that has its Status set to "Chapter Start" will show in that TOC.
Remember: the first page of each chapter should have Status = Chapter Start.
Then each chapter will have a TOC known as the "Chapter Contents" which includes all of the section titles unless you have checked the "Hide in TOC" check box.
While this is unrelated to the TOC there is also a check box labeled "Hide Title" which simply hides the title in the course display. It is very helpful to have each section titled and we strongly encourage you to do so but often you may not want to display this title for whatever reason.