The Italian passport is the 3rd most powerful in the world, allowing access to 178 countries, according to Global Ranking – 2018 by Henely & Partners Passport Index. So, if you are an Italian citizen, you can travel to America under the US Visa Waiver Program (VWP), which includes Italy. However, you will need an Electronic System for Travel Authorization (ESTA) prior to boarding your flight. The entire ESTA process can be completed online.
If you are planning to visit the US, I would suggest that you to apply for the ESTA at least 72 hours prior to departure. However, the VWP is applicable only to certain types of travel or nature of visit.
Travel Permitted Under the Visa Waiver Program
You can visit America as a tourist for vacations to visit a family member or friend. The VWP also allows you to travel to USA for medical treatment and to participate in social events hosted by social organizations. Your travel will also fall under the US VWP if you are going to participate in a sporting or music event or other recreational events that do offer any monetary compensation. Joining a crash course is allowed as long as it is not crediting towards a degree.
You can attend business, educational and scientific seminars or visit the country to sign a business deal under the VWP, using an ESTA.
If you have any questions please ask in comments.