You are looking good to have just started riding western!
I used to ride western pleasure and horsemanship, now I just show in reining.
Try to sit deep and keep your body straight and tall. Western pleasure is about making your horse look smooth and pleasurable to ride. You don't want to be moving your shoulders or upper body very much because it can make the horse appear that you have to really "work" to be able to ride him.
If I were you I would start working on riding one handed in split reins as soon as I could. Work on keeping your hand as low and as close to his neck as possible. If you get used to two hands and contact on the reins for control then when you get in the show ring and you have a long rein you might feel as if you don't have any control.
When you come to a fast stop you need to sit deep and rock your hips forward a bit, you must brace with your feet and NOT with your knees. If you brace with your knees then you will fly up out of the saddle.
When you pivot or spin, get your balance in the middle of the horse and then as he begins to spin around focus your eyes in front of you on any object and just keep focusing on objects as he spins around. This will help with balance and posture.
Most of all just get out in the arena and mess around with him, try to figure out his precise buttons and cues. Good luck and HAVE FUN!
I think he would look great in colors such as turquoise or navy blue.
This video is older but it is still informative. Be sure to pay attention to the rider's body position at the lope and jog- http://www.youtube.com/watch?v=WVZfC-uGMOo