Make the /courses/ page open to non logged visitors and display of the course_details page

We want most of our courses to be open and available for all visitors on our site. I don´t find where to set this preference and make our courses visible to all. When I visit our site without being logged in, I don’t see anything on the page: /courses/ only No results found.

Another problem is that I can´t find how to view the course_details page. We want this page to carry information about the course that the student can read before he or her enters any of the unit pages, but now it only display a few words in the first sentence.