From the dying planet Krypton, young Kal-El was sent to earth in a rocket as his home planet exploded behind him. The rocket crashed to earth where John and Marha Kent found the infant and brought him back to there house, adopting him. Clark. Clark Kent. They named him that. As he grew he had a normal childhood, until 13 years old. He started gaining abilities he never had before. His parnets finally told him the truth. He decided to use these powers for good, and he decided to wait a few years before doing that.
Clark finished school and went to college. He finished with a degree and moved to the big city: Metropolis.
Clark got a job at the the Daily Planet as a reporter and finally decided to use his powers. For the first time a 33 year old Superman was ready to start his career. He even got in a relationship with another reporter named Lois Lane. That was how Superman started.