You must be 21 or older.
21
No, you can carry a gun in your vehicle even if you do not have a concealed license if you are 18 years old or older. You must however carry it correctly. It must NOT be readily accessible. You can carry it in the glove compartment locked or unlocked. In a holster with a snap that is snapped. In a locked or unlocked gun case. Any box or case with a cover that is closed. It just CANNOT be readily accessible for quick use. http://www.solerslacklaw.com/Criminal-Defense/Florida-Gun-Law.aspx
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
(in the US) The laws of the individual states vary - but usually you must be legally an adult to obtain a CCW (concealed carry weapon) permit.
Pennsylvania doesn't require licencing to purchase ordinary Title 1 firearms. For a concealed carry permit, you must be 21.
You don't need a license to carry a paintball gun in the United States. To purchase a marker you must be 18 , to play at a field, insurance requires that you be ten, but can sign a wavier for yourself at 18.
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.