Nothing in Italy happens without a tax number (codice fiscale or Steuernummer). Therefore, the first stop you’ll need to make for administrative paperwork when you arrive in South Tyrol is the Italian Revenue Agency (Agenzia delle Entrate or Agentur für Einnahmen), where the process of obtaining a tax number will be both free of charge and easy.
What is required to get a tax number? You’ll actually only need a copy of your passport, an address (a temporary address is sufficient), and a completed application form.