First - OP, I am an FFL/SOT (Class 3) but you really did not give enough information to be able to give a good answer. I can say that if someone GAVE you this firearm, and it requires a federal tax stamp, the giver broke the law, you didn't but you may be in possession of an illegal firearm (a whole other matter). So much depends on what it is, how old it is, has it ever been registered before, and on and on. If you want to message me with the info I can maybe help you out. Worse case, give it back to the owner until it can be made legal. Or, get a lawyer involved, specifically a lawyer that is VERY familiar with Florida AND federal gun laws.
To transfer a AOW firearm, the transferer and transferee have to submit a ATF Form 4 (ATF Form 5320.4) and pay the $5 transfer tax and then when approved the AOW can switch owners.
If the owner/giver of the AOW has died, and the will designates you as the receipient, and the AOW is registered, federal papwork is still required. Any SOT can do the required Form 5 and there is no $5 tax due. However, if it is just coming from an estate, the a Form 4 and tax must be done (by the estate manager).
Second - Kevin, YES you can GIVE a firearm to anyone who can legally own/possess a firearm (following any/all state and federal laws). There is no law that says you have to accept money (or anything else) to transfer a firearm to any other person. Now in the case of a NFA item (SBR, SBS, Suppressor, Fully automatic weapon (machine gun or machine pistol), you can still GIVE it away but it has to be transferred legally through the NFA (National Firearms Act) Division of the BATFE (the tax stamp people) by doing the BATFE Form 4 and paying the for the tax stamp.
Mobuck I just saw your post. The only people who can do no tax Form 3's are SOT to SOT. In this case it would be a Form 4 from the owner to a SOT and then a Form 4 from the SOT to the new owner - UNLESS both parties reside in the same state AND the state laws allow the giver to transfer to the new owner without using a FFL/SOT and then it can be a single Form 4 from the old owner to the new owner, no FFL/SOT needs to be involved.
Disclaimer - I am not a lawyer, I have been a FFL for 36 years and a SOT (03) for 10 years but I am also a human, so I can make mistakes (but I learn from being corrected).