I just went through this with a friend *just* slightly older than you but, seemingly, very similar. It's amazing and wonderful that you've gotten to this point in your life without accumulating credit card debt! Stop and give yourself a pat on the back for that because, truly, very few people pull that off. You are very responsible and you should be proud of that.
That said, HAVING a credit card doesn't mean you need to go into DEBT! Using credit wisely will probably come naturally to you. As samhradh noted, if you never carry a balance, you're never in debt. Simply having credit is not the problem (my friend thought the same thing...just HAVING a credit card was bad).
Absolutely apply for a credit card to build your credit and provide some convenience and, possibly, rewards. Check into fee-free rewards credit cards where you might get something back from using them. Regardless, consider some of the benefits of having a credit card. I turned my friend from credit-free to a card holder when he booked a rental car for us on a vacation, and then was hassled trying to use his debit card to ultimately take it out (I didn't know before this that he did not have a *credit* card, and he volunteered to take care of the rental car since I used my airline status for freebies on the flight and hotel). I stepped up, dropped my *credit* card, and we were on our way. Sure, that's not entirely fair, but it's how things work currently. Not to mention that he was expecting to pay for extra insurance since he drives a beater and his insurance wouldn't cover a nice car, but I was able to say "don't worry about it, my credit card covers the CDW so long as I pay for the rental with the card."
Once you get a credit card, just use it for things you're going to buy anyway to keep it active. Maybe put your cell phone or internet bill on it, or buy your groceries on it. Then pay those purchases off immediately...you were going to spend that money anyway, right? Once you "get used to" putting things on the card and paying them off, use it for more purchases YOU WOULD HAVE MADE ANYWAY to take advantage of rewards, if possible. If you ease into using the credit like cash, you can make out like a bandit without paying a penny of interest. And, you will improve your credit and grow your available credit easily.
Good luck. It sounds like you've been very responsible up to this point, and you CAN use a credit card responsibly.