Hi
There is a free shuttle bus from the ship to the town .. a walk to the train station would take about 5 mins ...from where you depart the bus...
also ther are taxi's waiting at the port . would cost about 10 Euro [ that's the price they were last April to the ship... the cost to Termini Station is 11 Euro... alway's remember to valid all train tickets .. as the conductors will try and hit you with fines...