If you join a local GMO, and you did not previously have a USDF membership, you will automatically receive a USDF member number, right? Or would you need to apply separately?
You will get a USDF GMO membership number when you join your GMO.
This will get you into a show and allow you to get scores for rider medals, but for Regional qualifying and year end horse awards, you would need the separate Participating membership.
After your GMO sends your name in as a member, you ARE a Group Member of USDF. You have a number. Go to the USDF website and look under “membership” and go to “print card” - you’ll find your number and be able to print the card: http://www.usdf.org/card/