Moving to Orlando, FL, what areas are AT&T Internet fiber available.

Go here https://broadbandnow.com/ATT, click the map to initialize it and then input a zip code.  Once it loads click the Fiber tab at the bottom.  This will get you a general idea of where fiber is but understand two things.....one, it's not "live" data and can be as much as 6 months old and two, AT&T isn't known for great record keeping so I wouldn't take it as gospel that a specific address has fiber.

For a better look at individual addresses use the AT&T Availability tool.  Check the specific address and then check a few addresses on either side of that address (same side of the street) to see if they agree.

And finally, even that last tool can be wrong (AT&T recording keeping).  🙄