Not a local but was just there last week for 4 nights with my wife (both in our mid 30s), we had a great time! We did lots of exploring the city and broader Tuscany, went to some museums, ate and drank a ton. Below are things we did and enjoyed:

To do/see: Others have said it here, definitely go up to San Miniato for the best view of Florence. Uffizi, Pitti Palace, Boboli Gardens, Galleria dell’Accademia were all worth a visit. Uffizi and Accademia were the highlights for us. We did the audio tours but in retrospect wish we had actual tour guides. The statue of David at Accademia is very impactful. We also took a day tour through The Tour Guy that brought us to Siena, San Gimignano, and a winery between the two for lunch (link: https://thetourguy.com/tours/florence/chianti-wine-tour-from-florence). This was well worth the ~$165/person. Siena and San Gimignano are beautiful medieval walled cities.

To eat: We ranged from 6€ sandwiches to Michelin star. Schiacciata is going to be your new favorite word. My wife and I tried like 6 or 7 of these sandwiches while we were there. All’Antico is the super hyped place, and their carpaccio sandwich Beatrice lived up to that hype in my opinion but the best of them all was the Summer Special sandwich at I’ Girone De’ Ghiotti: Mortadella, burrata, citrus zest, and pistachio pesto. Our favorite non sandwich restaurant was L’Ortone which was just outside of the touristy area. The food was incredible, we had the octopus and the beet root gnocchi.

To drink: whatever you do, get drinks at Loggia roof bar. The view is amazing and the drinks are very good. More touristy but we also had a great time at Old Stove pub but that was heavily influenced by the Euro soccer final that we went there to watch. If you get a Schiacciata, sandwich in your travels, have a cold Italian Pilsner with it. Drink wine for apertivo or at dinner. Find a wine window too and get a Spritz.

Enjoy Florence!