It’s a beautiful city. Visit the Doumo. Not sure if you like museums, but the Accademia and Uffizi are worth seeing.
Choose small restos outside of the busy tourist areas. Up to this day, id say that I ate the best Bolognese at a small resto walking distance from the train station.
It’s the most wonderful city, the only problem being the number of tourists. Just wander around, and try to get off the beaten track. Two specific suggestions. Palazzo Pitti (more fun than the more famous Uffizzi in my opinion). And take a bus up to San Miniato, a wonderful monastery from where there’s a fantastic view across Florence.
Also, if you are interested in reading about Florence before you go or when you are there, I have a couple of suggestions. Not guidebooks, novels set in Florence. If you are interested, let me know.
Go online and look at what to do for vacationing in Florence. Usually you will find various day trips.......dinner shows.....wineries for tour...etc. You can select what you want to fill the time you are there. LOOK AT ALL DATES AND TIMES TO BE SURE NOTHING CONFLICTS.........and you can buy those on online. Print and keep the receipts and when you get there just present the paid slips for each event you choose.
The museums there are stunning, and there are outdoor sights like the gardens, Piazzale Michelangelo and Ponte Vecchio. They have a traditional food called lampredotto. It’s cow stomach (tripe), good on a sandwich, but maybe not for the picky eaters.
It’s hard to have a bad time or a bad meal there. The rooftop tour of the Duomo is incredible. And I love the wooden Donatello sculpture of Mary Magdalene in the museum there.
I was there a very long time ago. I recommend the flea market...they have nice souvenirs, cheap! I bought a copy of the statue of David, but they had copies of ALL the famous statuary.
Not in Florence specifically, but if you have enough time I'd try to see some Tuscany's west coast (and even the islands), not just the interior of the region ... and sample some Brunello, Chianti and Vernaccia di San Gimignano wines (but not pointless "Super Tuscan" blends of native grapes with non-native grapes like cabernet)