June Three Day Florence Itinerary Suggestions

I think you should get advance tickets if possible, especially with only two days. Last year we were there in May and the lines to the Duomo, were very long. We had been inside before, so it wasn't a problem for us. Same for the Pitti Palace and the Bardini Gardens. There are many churches in Firenze, so do some research and pick the ones of most interest. Same with museums. Some are small l, some larger and require more time. Depends on which ones you choose. History is everywhere. You didn't mention art, but of course there is the Uffizzi. (Definitely get advance tix) Our favorite is the Bargello, if you like sculpture.
The Galileo Museum was an unexpected delight, and we were able to walk right in.

After Florence, we spent 4 days in Siena. Wonderful city. The Duomo complex is fabulous. You can visit the Palazzo Pubblico, The Piccolomini Library or Basilica San Francesco or any number of other interesting places. But with only one day, the Duomo Complex should be the main event.

Online googling with help you with your choices.

Thank you for your suggestions. To clarify, the day trip to Siena is a fourth day, so we have three full days in Florence. It seems the Firenze Card only includes museums, not cathedrals. I am leaning towards getting tours to limit group size since it will be high season.

It seems the Firenze Card only includes museums, not cathedrals.

There is only one cathedral in Florence: Santa Maria Del Fiore. It is a complex of multiple structures and they are not covered by the Firenze Card. The website for ticketing is here, and the cathedral (duomo) itself - other than to climb the dome - is free thus can have long lines. Passes are required for the dome, museum, baptistry, bell tower and subterranean remains of Basilica of Santa Reparata.

https://duomo.firenze.it/en/home

But there are many other churches in Florence, some of which are free and others which are covered by the Firenze Card. That card is only worth the price if you can break even on the price versus individual entry fees for the attactions you wish to see. Do understand that the Uffizi, Accademia and Brancacci Chapel require advance, timed-entry reservations if using the card. Some churches covered by the card:

Santa Maria Novella
San Salvatore in Ognissanti
San Lorenzo & Medici Chapels
San Marco
Santa Croce

I wouldn't say that the card is worth the price for just these churches; pay for them individually. In addition there are some great Florentine churches that can be visited for free:
San Miniato al Monte (a must-do)
Basilica Santissima Annunziata
Santa Trinità
Basilica of Santo Spirito

I don't think the FirenzeCard is a good idea with on;y 3 days.  A couple of weeks ago another poster asked about it and from what I remember, with the card she came out ahead by a few dollars but she was in Florence for 5 days and going to lots of attractions each day.  With only 3 days I doubt it would be worth it.

I don't think you need tours, I would recommend just buying tickets on your own.

Thank you all! I will buy tickets ahead of time for sure!

We really loved the Secret Passages tour at the Palazzo Vecchio. You learn really interesting history about the Medicis, along with art and architecture. It was a highlight for sure!!