As per your information, it looks like you haven't set any course page for start. below are some steps to do so:
- Open admin page and add a new page with any name related to course status. in this page choose template- Start Course Page.
- Open admin page and go to WPLMS and open COURSE MANAGER. screenshot attached: .http://prntscr.com/lrtlka
- In COURSE MANAGER page you will find a option "Take This Course Page", set it to the same page you created in first step.
Now you can access courses by clicking on start course.
If further any query left, Please create your own topic and share the details about the issue we will be happy to help you.