They plan their flights-where, when, how high, how fast, and more. They have to get their crew ready, check the aircraft to make sure it's okay to fly, and know about the weather. You must have a lot of energy, be very organized, and pay attention to details. Of course, you need to know how to fly. Even then, pilots need to fly many, many hours before they can work for an airline.
Many pilots learn to fly and get their experience in the military.
Others take flying lessons, become flight instructors, and get jobs that start with flying small planes. Usually, you don't need a college degree, but it helps. Being good in math helps too, because pilots must handle a lot of numbers and details, plan, organize, and think clearly to make decisions. Math and science help you to do those things. You should find out all you can about aircraft and flying.