Get your Codice Fiscale first
Before you arrive or Day 1The codice fiscale is Italy's tax identification number. You need it to sign any rental contract — without it, most landlords won't proceed. Get it at the Italian consulate in your home country before you arrive (free, takes 1–2 weeks) or at the Agenzia delle Entrate in Milan on arrival (free, same-day with your passport). Don't skip this step.
You can get a temporary CF from the consulate that works for rental purposes even before you arrive.