At an early age (college or your early 20s) you should get a credit card and use it. Wait. Isn’t that like telling a college kid to try crack?
For some kids, yes, a credit card is free money and they treat it like such — running up huge balances that they can’t pay off. But for young people with their act together, using a credit card in a sensible way (charging something and then paying it off immediately) will actually boost their credit rating and make it more likely that they can get a mortgage or car loan in the future.
A bad credit score, on the other hand, can haunt you. Some employers use them to screen applicants and landlords can deny renting to you if you they don’t like your credit history.