Salerno is well connected by train to Pompei main train station. A direct train ride takes 25 minutes. Indirect trains, 45 minutes. You pay € 2,10 per person for a ticket which is valid until 100 minutes after you stamp it. From Pompei main train station it’s about 1 kilometer walking to Pompei Scavi. When you exit the train station, go to the left. A long time it will look like you are going nowhere, but after 800 meters you arrive at a green park area, the outskirts from the Scavi area. Continue a little to find the entrance.
TIP: If you want to see places like Naples or Sorrento, take the Circumvesuviana train in front of the Pompei Scavi entrance. It’s different from the main train station !
Salerno train station is located at Piazza Vittorio Veneto, which is on walking distance from Piazza Della Concordia and the Porto Turistico and the shuttle bus stop.