The train from Rome takes 2 and a half hours arriving at Napoli Centrale which is located at the edge of the city. It is important to be aware of your belongings at this busy station. From here you can use the underground metropolitana to get to various parts of the city. City and suburban buses stop on Piazza Garibaldi but the best way to explore central Naples is on foot. Naples is a big and spread out city and taxis may be a good option if you wish to venture out beyond the city centre.
The proximity of Naples to Rome makes it an attractive choice for your Italian trip which combined with the scenic Amalfi coast, Pompeii and mount Vesuvius will give you a rather unique range of experiences. Naples airport Capodichino is around 7 km from the city centre and there is a regular bus to Piazza Garibaldi from the airport which runs every 15 minutes.