Spring (April to May) and Fall (October to November) are great times to visit Italy because it's warm and there are fewer tourists. If shopping is one of your main reasons for visiting, you may want to avoid visiting Italy in August. August has a traditional Roman holiday called “Ferragosto”, and many businesses will be closed during the time.
Ground transportation: depending on your arrival city, the ground transportation options will be different. From the Rome Fiumicino airport, you can get to downtown by taking the Leonardo Express non-stop train. There are 3 subway lines that can get you to many attractions in Rome. Stazione Termini is the transportation center station of Rome. You can access the subway lines or the Eurolines coach buses from the Stazione Termini.
Stays: Airbnb provides vacation rental home resources to people who are looking for a more personalized and private experience. VacationHomeRents can help you compare the vacation rental homes rate from different platforms in one place.
Visas: For US citizen travelers, visas are not required to enter Italy. For non-US citizen travelers, Schengen visas might be required. When planning for your trip, check the official Italy travel advisory posted by the US Department of State. If you encounter emergency situations or need assistance, contact the US Embassy in Italy for help.