The most important thing in showing a livestock project is to know the rules. Before you buy your goat, before you build your facilities, before you buy anything know the rules.
Most shows require the baby or milk teeth to be present when a market goat is shown.
Does your show allow horns or does the goat have to be disbudded. Goats can be dehorned, but it does set them back quite a bit, and takes a long time to recover. Don't buy a goat that is going to be too big or too small for your show. Different judges have different preferences. Goats are herd animals.