If not you should get one as soon as possible.
Why?
Well contrary to popular believe, especially in the United Snakes, credit cards are not a bad thing. They make things cheaper for you, they provide you many protections, they may even give you free money (rewards/bonuses), and they can get you out of a bad situation if you really need that and you have absolutely no other choice.
The sooner you get one means the sooner your credit history starts and your cards age, which means a higher credit score.
You probably shouldn't go apply for a "real" credit card or one with good rewards, such as (X) amount of money if you spend (X) amount of dolars. You simply won't be approved for that.
Go get yourself a secured card, or a real garbage no-rewards card from some big company, as big companies while they're destroy the world with your support, they won't be as likely to screw you over directly.
Realistically any will work, but currently, at least in the USA, the best card to start out with is this guy, the Discover It secured version, and while it will cost a couple hundred to set up, it'll build your credit and naturally upgrade off that scum-bag secured status after a handful of months.
Other cards often do not upgrade (or have any rewards) and thus you really lose out and potentially may even have to close your account (or prefer to) as secured cards look bad and are often not willing to be upgraded, so make sure you can get rid of that sucker and upgrade no matter what later on, as closing your account not only takes away age, but also generally looks bad.
As long as you don't act like 90% of the population and use it as if it's a credit card, rather than as if it's a debit card, then there's no reason not to get a Credit Card and get one as soon as possible.
