The requirements for claiming the homestead exemption in the state of Florida are spelled out at the website for the Volusia County Property Appraiser. The link is shown below:
I imagine most of the Florida counties have a similar website that provides this information.
The key factor in claiming a homestead exemption is to prove that the property is your primary residence. As the website indicates, you'll need to be prepared to show that you're a legal resident of Florida.
You do that in various ways, for example by providing evidence that Florida is where you're registered to vote (or where you have a "Certificate of Domicile", as well as showing that Florida is where you have your driver's license, and automobile registrations.
There are several different exemptions available, besides the basic one, including those for widows/widowers, senior citizens, persons with disabilities (some exemptions specifically for veterans and others for members of the general public). Double-check that you're claiming all you're entitled to.
And please take the time to check that everything you're doing is legal. Penalties for making unsubstantiated claims are severe and can go back as far as 10 years.
I'm not a lawyer, and this is not legal advice, but if you have any doubts, call a lawyer. Many will provide an initial consultation free of charge. Good luck.