It's possible to walk, but you'd probably be happier not to with bags (it's about a mile). Most of the time when ships are in port there is a shuttle from docks to front of the port, and then a bus to the train station. Or you can take a taxi, which costs between about 13 and 20 Euros. You can check for trains from there on the Trenitalia web site.
Thank you. We've got the train lined up. Can a taxi pick us up at the dock? Or we need to take a shuttle and then the taxi can take us to the train station?