Further answer to Jim's question:
Because you're a first time driver in Italy, I'll add this: A number of first time drivers to Italy have been blindsided by the degree to which driving in Italian cities is, for many, significantly more challenging than driving in cities here or in other European countries where driving is easier than Italy (Germany, northern France). This is difficult to put into words, but you'll know what is meant after the first day driving in Italian cities.
The advice usually given here is: avoid driving into the Florence historic center. It's not necessary and can cost you in both stress and fines (if you choose to pay them).
People have reported back to us that things they thought they were going to be able to do, such as have sufficient time to make turns and void the Florence ZTL's--well, it just hasn't worked out that way for some/many.
For these reasons, most people reporting in on this site have decided to arrange their trips so that they did not drive into the historic center of Florence, renting cars either before or after Florence, but not having a car overnight in Florence and not trying to drive into the historic center on a day trip.