good luck
If I am understanding war elephant correctly(and I have heard of this before with military youngsters as an example), you can legally own a handgun at 18 in NC. You just can't buy one from a gun dealer or establishment that sells guns. You can however(if all this is true) purchase a firearm from a friend.
Sort of like a car: write up a bill of sale that you both sign, save the original, and give your friend a copy if he wants one. Make sure to put the bill of sale in a safe place to store for at least some years. Bear in mind the bill of sale is technically not necessary, but I always recommend having one.
And no, don't try to have a friend buy you a weapon at a store or buy one for himself that you later buy. You shouldn't own a weapon if you do something so foolish(willingly commit a felony via a "straw purchase"). The only other issue is where you live and/or who owns the dwelling.
You need to double check and triple check to make sure this is legal in NC. If it is you are absolutely legal and legit if you follow these easy criteria + keep your firearm at home(exception: to and from the range in your personal vehicle unloaded and secured). It may seem like some pointless 'hoop jumping', but people buy guns from their buddies all the time. Personally, I have chosen delibertaely to buy every one of my firearms from a dealer. If I was 18, I would do it this way in a heartbeat though.
PS- buy a stainless steel revolver(just kidding: buy whatever semi, revolver, rifle, or shotgun you like)