Go to national and state meets and volunter to help out and be a training Judge.
Get hold of the organizers of the meets to get in touch with Cheif judge.
FAI has some links on their webpage including sample vedios to pratice on.
Judging is hard work But can be very rewarding. You meet a lot of people and go a lot of places.
I have judged meets in Canada, Aussie, NZ, Malasia, since 1976 (off asnd on) And have had a great timed doing it.
Nowadays I only do NZ POPs meets but still great fun and people. Watch my video Fat Women