You must create an account to share a course. Then you can share your course by clicking 'add post' located un header or by clicking the "+" symbol under the search bar.
First is the title (you must indicate your course talks about, like History, French etc.)
Then description, tell informations than should not appear in the course form.
And you finally end with the course you wanna share: Just write down or copy paste the course's content you want to share.