roll as many times as you can. practice in the flatwater until it is second nature.

the only thing that jumping into holes is going to do is flip you in moving water and make you more scared than you already are. if you hop into some small shallow hole and get flipped you could injure yourself pretty easily.

once you have a roll and can hit it in moving water, then you will be ready to start playing in small holes. surfing holes and getting flipped a bunch of times will help you dial in your roll to the point that you will almost never miss one, but you need to have a basic roll first.