2 days in Florence. No museums

Great walking around City. Impressive façades with numerous architectural detailings including many with Art Deco highlights. If you're exploring across the river, Zeb would be an excellent choice for lunch - work your way past the TA reviews. The food and wine offerings are solid, give the owner some latitude with his manner ie. let him work through his opening spiel, then jump in with questions and ordering, and you should have a nice time.

One of the highlights of Florence is the Duomo. You can even climb to the top. https://lyssyinthecity.com/2023/07/18/florence-climbing-the-duomo/

Florence also has some wonderful parks and gardens.

https://theculturetrip.com/europe/italy/articles/the-most-beautiful-parks-and-gardens-in-florence

Maybe shopping is your thing.

https://www.walksofitaly.com/blog/things-to-do/shopping-in-florence

Or a food or wine tour.

https://www.tasteflorence.com/

Churches
Santa Croce with all the tombs of famous people
Santa MariaNovella
Orsanmichele

Mercato Centale -have lunch or dinner upstairs
Hike up to Piazza Michelangelo for the view
Take bus up to Fiesole

San Marco Museum usually not crowded a bit different than others-frescoes

Bargello -sculptures

Look at the map for Santa Croce, San Marco, Santa Maria Novella and the river and walk all over the area between them but concentrate a bit more around the Duomo and Piazza della Signoria.

I agree about San Marco and the Bargello. They are great museums that are quick to see and no lines, so break the no museum rule and see them.

Chiesa di San Salvatore in Ognissanti and Basilica di Santa Trinita are beautiful churches, pop into them for a few minutes.

Look at the sculputures in the Loggia dei Lanzi and walk around the Church of Orsanmichele to see the sculptures (replicas but still nice to see).

Thank you for the excellent suggestions. Now I know what to do.