Ciao Matt and welcome to the forum!
First of all, I'd recommend you read this article on how to get to the Mugello race track as it offers various alternatives:
http://www.discovertuscany.com/mugello/mugello-circuit.html as well as the last posts on this
older thread that offer suggestions from people who went this past year.
I'd suggest to plan to arrive to Florence/Tuscany at least a day before if you can, you don't want to arrive and head out to the race track directly just for the weekend. It would be easier to stay in Florence, leave suitcases at your hotel or B&B and go out to the race track every day. Otherwise, you could also stay in Mugello but that weekend gets sold out really early and you might already have trouble finding lodging for that weekend - pretty much everything all over the Mugello gets booked months ahead of time. Mugello also really requires your own transportation to move around so if you don't want to drive, Florence is your best alternative.
If you still have questions after reading through those two articles, let us know!
