I'll answer your chicken questions, as I'm not a goat expert. Rouen ducks go under the "Heavy" class of duck. Wyandotte chickens, if large fowl, are in the American class. If bantams, they go in the Rose Comb Clean Legged (RCCL) class.
Most county fairs are set up like this: Birds are "cooped in" a few days before the show. They are in there own cages, and you have to provide feed and water, as well as feed and water cups. On the day of judging, a judging row of cages will be erected. When your class is called, you take your bird up to the judge and put it in a cage. The judge judges all of the birds in a specific class, and awards ribbons.
You can also do showmanship at a poultry show. In showmanship, you display your knowledge of chickens and poultry in general. You are asked questions regarding defects, disqualifications, breeds, breed classes, parasites, diseases, etc. You are also judged on how well you handle your bird, including putting it into and taking out of a cage, posing the bird, and handling it.
Hope this helps!
