You cannot carry a gun in England, indeed you can be arrested on the spot for carrying anything more dangerous than a pen-knife. You also cannot own a gun unless you have obtained a licence to use it for sporting purposes, and you need to be 18 to do this.
21
Three.
The state of Illinois does not issue carry permits, so it's illegal at any age to carry a gun in Illinois, assuming you mean out in public with a gun permit.
In PA you have to be 21 to conceal carry (or carry loaded in your car) a handgun.
18 to purchase
AFAIK, no.
You must be 21 or older.
Guns are illegal for any age in England, unless you are a police officer.
18+ but any age to wield it
You will have to define what you mean by carry, and which gun. There is a large difference between carrying a concealed handgun, and carrying a rifle or shotgun when hunting.
What kind of license? Where are you? What kind of gun? to carry a gun north America pistel It depends on where you are. In some states, you have to be 21 but in a few, you have to be 18.
It depends on where you are and what you mean by gun license. If you are in the U.S. and you mean a permit to carry a gun, check the related link for information.