As Kathy mentioned, Walks of Italy is well regarded. We took two tours of Florence with them. We took the morning walk of Florence which includes tickets to the Accademia to see David. We were given an hour there, which is plenty of time to see David, but not enough time for a deep dive in the museum. From there we toured the Duomo and did a general walk through the heart of the city.
In the afternoon, we took the Uffizi tour. Again, skip the line tickets were included. Our tour guide Marco has a Master's degree in Art History and he provided some great back stories to what we saw. There were only 6 of us on the tour, so he didn't use his radio microphone. The Uffizi was open late the night of our tour, so we had plenty of time after the tour to explore on our own.
Have a great time on your trip! My wife and I were fortunate. Our first visit to Florence was on a school trip in August 1966. We got to see the original Gates of Paradise panels on the baptistery door. That Fall, there was a terrible flood and the panels dislodged. Luckily, the gate around the doors trapped them and kept them from washing away.