You need to tell us more about the "gun license" and for what area. There are many different gun licenses.
you can be 10 but you need a hunters license
That depends if your state requires a license. Most don't.
You don't need a gun license if you are 25 but if your under 25 you do need a gun license
It depends on where you are and what you mean by "license." In the U.S. in most states, you have to be 21 to get a handgun carry permit. In most states, you do not need a license just to own a gun.
No, you do not need a gun license to buy magazines.
You need to contact your local authorities.
You never need a license to have an Airsoft gun.
No, you do not need a license to purchase gun magazines in most states in the United States.
To get a gun license you would need to go into a gun store in the town you live in and ask for the information you need.
No.
yes