Mega Man’s original name in the games is Rock. Dr. Light created Rock as a laboratory-assistant robot before modifying him for combat, after Dr. Wily reprogrammed Light’s other robots for a takeover attempt.
The name is part of a paired wordplay with Rock’s sister robot, Roll. Together, “Rock” and “Roll” reference rock and roll music, while the original Japanese name Rockman also became the title of the series in Japan. Capcom changed that title to Mega Man for the North American release.
Rock is not a human being; he is a humanoid robot or android. The question’s wording can therefore cause a small mix-up, but “Rock” is the canonical original personal name for the character. After his conversion, he becomes Mega Man, commonly known as the Blue Bomber.
The transformation also explains why early stories describe him as a helper rather than a warrior. His combat role is voluntary: Rock chooses to be rebuilt so he can oppose Wily and protect the world. Roll remains primarily a support and household robot in the classic continuity.