Every single person, pretty much, is taught what they're supposed to do: go to school, get a job, find someone to love, get married, have kids, raise the kids, and then die. Nobody questions that. What if you want to do something different?
A comedian (comedienne for females) or comic (a professional comedian/comedienne) is a person who seeks to entertain an audience, primarily by making them laugh. This might be through jokes or amusing situations, or acting a fool, as in slapstick, or employing prop comedy.