My first show i went into Novice classes, it was fun because everyone was new to showing and we all had a chance at placing going in, it also helps take the pressure off you and as a result your horse. Your boy is an old hand at showing if he's been before so likely knows his job going in. But a novice class is a great way to go in and get to know what the shows are like.
If youre going into liteshod, they are looking for the horse that walks the fastest with the most animation. Also make sure that in the liteshod you know the kind of shoeing, up here in Canada it doent make a big difference as we're all in regular shoes, but there is padding, weights, etc in USA and you want to know you go into the proper class for your shoes.
Other than that, just have fun!! He's a very nice looking guy!