Choose a heroic figure you have read about. Examples might be: Theseus, Oedipus, Calaf in Turandot, King Arthur, Siddhartha, Moses, Mohammed, a cowboy hero, or Frodo from The Lord of the Rings.
Other examples may include people who are/were known for their humanitarian efforts, or who have led a movement (such as Mother Teresa or Dr. Martin Luther King Jr.).
Or, choose a heroic figure from a book, a film, or a comic/cartoon series with which you are familiar.