Call or write to American Field and find out what types of trials are being held in your area. You can also visit their website at
www.americanfield.com
All trials that I know of allow visitors to be a part of the gallery, and some even let you go along with the brace.
As far as hunt tests, they are not a competitive venue. They simply award a certificate if a dog can meet a certain set of standards for level of training.
If competition is your cup of tea, by all means go to the nearest American Field-sanctioned trials...you'll get bit by the bug in a hurry!