Basic pointers. Eurostar mostly covers big stops: Rome, Naples, Venice, Florence, Bologna, Milan, and a few others. Not Pisa. Eurostar does Rome to Florence, then Bologna to Milan. It’s mostly a north-south line because it crosses the border into other European nations. You can use it from Rome to Milan, and vice verse. From Milan you can catch a trains west to Venice. Or, you could take the famous Rome-Venice train, the Freccia della Laguna, about six hours. Italian train travel is fundamental. Don’t worry about finding tickets on the travel day. Assuming no strikes, you will. First class, while pleasant, is merely an assurance you’ll sit. In second class, it’s closer to “all aboard.” Assigned seats are fewer. But don’t get upset by the website. You can buy your tickets in Italy at a travel agency or at the station. Do remember to validate the ticket before you board. You’ll see yellow machines (Ok, some may not work, but find one that does). Fail to do that and there’s an outside chance you’ll pay full fare and a fine