The airport's website you can provide all the information. If you take the bus, you get off the public gardens of Via Catalonia and take Via Roma until you find next to the Tower of the Cathedral. The street on the left is Via P.Umberto. The Historical Center is subject to limitations with regard to traffic and non-residents can enter by car from 8am to 10:30 am and from 14.30 to 16.30 pm. You can easily park in a large parking located in Piazza della Pace (seafront before arriving at the port) which is 5 minutes from home.