Ha! Your question was the very first question I asked on this forum 9 years ago, and it was Kate from Minnesota who answered me first.
In 2017, in Florence for a month, I decided to get the booklet of tickets instead of any pass, and I did the same thing in Florence for another month in 2024. Next time I might try the tap and pay, although actually I would rather have a paper ticket ready to go than hold either my phone or my credit card in my hand. I wish Florence had a nice little card to tap, like the vaporetto pass in Venice.
There is a bus app that will tell you how to get from one stop to another, but I found it much easier to use Google Maps --- you can see where each bus stop is and which buses stop there. Again, I wish Florence had a regular map that showed the bus routes like it used to, either online like the vaporetto maps or on paper. Much more user-friendly for a tourist. You might want to do what I did, and make your own bus route map so that you can see what is along the route that you might want to also visit.
I'm mainly talking about the cute little hybrid buses that go closer to where you probably want to go than the bigger city buses.
Have a wonderful time!