According to the UNIFI guidelines for the next semester, classes will be in the presence

  https://www.unifi.it/insiemeinsicurezza (it is in Italian, but you can easily translate it online).

If you are not in Florence yet, you can start your career as Auditor (uditore), which is not an official enrollment but will allow you to access the didactic material made available through the moodle website of the single teachings. More information is here https://www.unifi.it/p12239 (this is in Italian too).

The process for temporary enrollment as uditore can be completed through  https://sol-portal.unifi.it/ls-3-studenti.html