After you have completed the steps on the Immigrant Visa Process on usvisas.state.gov, including paying the necessary fees and submitting the required immigrant visa application form (DS-260), Affidavit of Support, and supporting documents to the National Visa Center (NVC), they will review your file for completeness. Once your case becomes qualified for an interview, NVC will work with the U.S. Embassy and Consulates in Italy to schedule an interview appointment for you.
You can learn more about the interview process on usvisas.state.gov.
If your petition was filed with USCIS Rome, you will be contacted by the US Consulate Naples when they receive your approved petition. If you cannot speak Italian or English, you should bring a certified translator with you on the day of the interview and inform the Consulate in advance.
Instructions for Immigrant Visa Applicants (.pdf file)
Medical Examination (.pdf file)