Becoming a pilot is a challenging yet rewarding adventure. I’ve wanted to fly since I was about 7 years old and went to college to study aviation. The amount of required knowledge and studying surprised me. You will no doubt immerse yourself in the material and develop your knowledge as you train. However now is not the time to start learning things without any guidance. It’s possible to overwhelm yourself and become discouraged. During your training the Flight Instructor should provide you with the required information and guide you through the course.
In preparation for training you can familiarize yourself with some of the materials and literature provided by the FAA. The two links below have more information on becoming a pilot as well as downloadable manuals.
I hope this helps. Good luck!