For information on getting your codice fiscale (tax code) and your tessera sanitaria (health care card so you can access the national health service), you need to contact the Agenzia delle Entrate. You can find information and the forms in English here. If you do not qualify to have the Italian health insurance, and you need to see a doctor, you will need to find a private doctor. You can access that information here.
To be assigned a doctor, you need to contact the ASL Bergamo. It’s so long since I did this that I can’t remember the procedure — any readers want to remind me? Thanks!