Moved to the Florida forum.

Federal law is 18 to buy from a private seller or receive as a gift. The age for buying handgun ammo is 21, so there is still that problem even if FL law allows you to own a handgun. I'm really not up on FL laws other than open carry is illegal.

(5) POSSESSION IN PRIVATE CONVEYANCE.—Notwithstanding subsection (2), it is lawful and is not a violation of s. 790.01 for a person 18 years of age or older to possess a concealed firearm or other weapon for self-defense or other lawful purpose within the interior of a private conveyance, without a license, if the firearm or other weapon is securely encased or is otherwise not readily accessible for immediate use. Nothing herein contained prohibits the carrying of a legal firearm other than a handgun anywhere in a private conveyance when such firearm is being carried for a lawful use. Nothing herein contained shall be construed to authorize the carrying of a concealed firearm or other weapon on the person. This subsection shall be liberally construed in favor of the lawful use, ownership, and possession of firearms and other weapons, including lawful self-defense as provided in s. 776.012.

You may want to call your local sheriff's department and/or the FHP and ask them.

(16) “Readily accessible for immediate use” means that a firearm or other weapon is carried on the person or within such close proximity and in such a manner that it can be retrieved and used as easily and quickly as if carried on the person.

(17) “Securely encased” means in a glove compartment, whether or not locked; snapped in a holster; in a gun case, whether or not locked; in a zippered gun case; or in a closed box or container which requires a lid or cover to be opened for access.