As mentioned before it's pretty difficult to apply for a job as a crew member in the Mob. It’s even less likely that sending a résumé to the Commission to apply for the job as boss will get you anywhere. Just about all bosses, underbosses, capos, and soldiers either had fathers and grandfathers who were in the business or were close family friends of someone who was.
That being said, Henry Hill, who documented his experience as a mobster with Nicholas Pileggi in a book which became a movie, was only half Italian and didn’t have any familial connections to the Mob. He started out running errands for patrons at Paul Vario’s business. Vario was a capo in the Lucchese crime family. When he was 13, he started serving drinks and sandwiches at card games frequented by Mob members. He fell in love with the lifestyle, the money, and all that came with it. He eventually became an expert at arson, intimidation, and running a stolen car ring. The guy did well with his God-given skills. And then he did some bad things—both to his Mob family and to the public—and testified against his former associates to avoid execution by his crew or going to prison for his crimes.
Point being, Hill wasn't born into the Mafia, but he might have been born for it.