The University of Pisa is not a campus-based university so it does not have its own dorms. However there are various options available to students to find an accommodation.
Here some useful tips about how to avoid accommodation scams
The average rent for a single room in a shared apartment is between 300/400 euros a month
Please note that landlords normally ask for a deposit equivalent to one/two months rent upon signing the rent contract
You are strongly discouraged to pay for a long-term room before you obtain your Visa or you come to Italy.
If you want you can first book a short-term room (10 days/ 2 weeks) and then you can look for a long-term accommodation once you are in Pisa.
Short-term rooms bookings can be normally used for Visa purposes
In any case, always make sure to sign an agreement saying that you can have your rent/deposit back if for some reason you are not finally able to come Italy
Always get a rent contract!
Short-term rooms can be found here and here
Long-term rooms
Announcements by private landlors may be found here and here
If you have Facebook, you can have a look here, here and here
Other options are the housing platform Housing Anywhere and the Cerco Alloggio platform
If you are looking for a student dorm, there are several options available such as Studentato Cappuccini Hall, Casa dello Studente Villa Giulia, I Praticelli Residence, Residence Tulipan, Residence le Benedettine, and Pensionato Toniolo
Finally, there are dorms for girls only that are mostly managed by catholic nuns. Among them there are Pensionato San Giuseppe, Pensionato Santa Marta and Istituto Suore Figlie di Nazareth