Carry how? If you mean carry concealed, you need a Concealed Weapons license, or be a law enforcement officer.
No,
No, you only need a permit if you want to carry the gun in public.
At a minium, 21 for a hand gun and 18 for a long gun.
You need a license to carry a firearm in many places. You cannot carry one on an airplane.
To carry concealed, yes.
need state to see if it's open carry
If you are 21 and have no criminal record there is no requirement to have a carry license however you do need one is you wish to carry concealed.
You need to define the term gun license. In most of the US there is no license to own a gun. Some states require a license to carry a gun. others to carry a gun concealed. There is also a license to make or sell guns. All are different and have different procedures.
You need the services of a lawyer for a legally correct answer.
You will need to contact your local law enforcemnt for the answer since you don't mention what state, your age, etc..
Well, the answer is no, but Arizona does not have gun registration, so if you can carry a gun in Arizona, you can carry any gun you legally own or possess.
Yes, as long as you are also a resident of Florida. Sorry, I should have also said this: You can buy a handgun from a private party if you don't live in Florida, but to be legal, the owner would have to ship the gun to a dealer in your state, and you would have to pick it up there. There will almost always be a charge for that.