Florida is a little different when if comes to selling food.  In addition to state health and tax requirements, every county, city, etc has their own requirements as well.  Sometimes you need to jump through state, county and city hoops.  It is very likely you will have to pay more than the state 6% sales tax because most counties add taxes of their own.  The health and fire permits are also going to be ruled by the location of the festival as well as what type of deal the promoter has initially set up.

So the short answer is:

Find the events you want to sell at and call the promoters to ask them specifics regarding required, 

• Licenses
• Permits
• Taxes, and
• Inspections.

The shows should know exactly what is required of their vendors and this will be the best place for info.  Most shows fall under a ‘temporary’ jurisdiction that can waive a lot of headaches for vendors.  In the list of urls below, I’ve linked to a pdf with more info on temporary licensing.

If you don't fall under the "temporary" jurisdiction that prepare to spend some time getting your paperwork in order.  Food service in Florida is governed under a number of different agencies, but mobile service falls primarily under Florida’s Department of Business Regulation, and more specifically their Division of Hotels and Restaurants.

Important Florida Mobile Food Service Links

Florida’s Department of Business Regulation

Florida requires inspections of new mobile food dispensing units.

Florida State Annual Reseller Certificate

Florida Food Vendor Licensing Fees

Florida Temporary Sales Permit Information