You can learn to swim, learn to compete in swimming, learn to do all types of water sports and even learn to teach others to do these things in the right swimming school. Depending on how far you want to take your education, you could make it a career.
In some swimming schools, youll be able to compete against others when you get to a high enough educational level. Take the time to make sure that you select a school that does compete if this is something that you are interested in doing. Its a great thing to put on a resume, too.