No need to spend a lot of money here, especially if you are 18.
Best bet (IMO) is a leather billfold, dark brown or black. Not a tri-fold, probably like your velcro one. A simple billfold. Just type in "leather billfold" into google, and you'll get what I'm talking about.
-Keep as little as possible in it in the way of cards.
-It should fold thin, preferably kept in the front inside pocket of your jacket, if wearing one. Don't stick it in your back pocket. Might as well attach a damn chain to it and wear a ballcap backwards.
***A George Kastanza-wallet, you do NOT want.
You can grab something like this at any department store. Yes, you spend hundreds of dollars on a designer wallet, but seriously, would you rather have a empty designer wallet, or one that looks like a designer wallet, full of crisp 20's?

It's your call.
-Some guys also just use a money clip. Stylish, yet not pratical for plastic at all.