To create a course from scratch, use the create a new course button on the courses page.
Once you've given your course a name, this will open the course editor. There are guide boxes that will walk you through the process of adding to your course.
Once you finish editing your course, you can view it from your course management page under the list of draft courses. The actions dropdown will allow you to publish the course so it can be used by teachers and will be visible to students.