The first thing that you need to understand about bowling is that it is no different than any other sport, well except maybe the air conditioning. If you really want to learn to bowl you need to take your games very seriously. Concentrate on what you are doing and make sure that you have no distractions.
You need to first find a ball that will fit your hand and style of bowling. The ball you choose for the first few times might be something you find laying around the bowling center, but that's ok because no matter what ball you use, your form and technique will be the same. To find the proper weight of a ball you are going to hold your bowling hand out with your elbow touching the side of your body. Then have someone place the bowling ball in your hand. If you can hold the ball up go up in weight until you cannot hold it anymore. That previous weight will be the weight of the ball to use. If you are able to use a 16lb ball, I would recommend using a 15lb ball because the two weights hit the pins the same, but obviously the 15lb ball will have more power behind it because it is lighter.