Send an email to campusadmin@extension.org. 

Please review the information at extension.org/campus-procedures/. If you have other questions, send an email to cataloghelp@extension.org.

Course teachers have the rights to manually enroll people in their courses, and to assign those people to appropriate roles.  Go to the course administration block and select Users-->Enrolled users.  In the upper right corner of the screen will be an "Enrol Users" button.  Click that and a window opens up where you can search for the person you want to assign, as well as what role you wish to assign to that person.

Send a message to campusadmin@extension.org requesting a course shell.  In that message, include the title you wish to give to the course along with the names and email addresses of those who will teach the course.  The Campus site administrator will set up the course and notify you of its availability for you to begin entering the course content.

A simple web search will reveal a large number of websites with instructions or suggestions on how to do various things in Moodle.  But Moodle itself provides a very nice collection of brief (5 minutes or less) videos.  The YouTube playlist for that set of videos for Moodle 3.11 (current version) is available here.