Yup, read the book, watch the videos, take the quizzes.
Don't work too hard at this. Your instructor's job is to help you develop the skills and knowledge required for certification. If you have a good instructor, he/she will be there to help you when you stumble. A good instructor will also create conditions in the pool that are just outside of your comfort zone. The purpose is not to be mean but to develop skills and confidence. You will learn that you can swap dive gear on the bottom of the pool, leave the gear on the bottom, go to the surface, then do a surface dive and don the equipment at the bottom of the pool. All to help you develop skills and confidence.
Relax, enjoy, and once you have your cert, dive, dive,dive. By the way, you mask will leak on your first open water dive because of the huge grin.....its okay, you will learn to quit grinning, but you will still have the great feelings of euphoria when you dive. I have never had a bad dive, some are just better than others.