travel from Calabria to Sorrento

I don't think trains are dirty (except the dirty-cheap - pun intended - Espresso night trains that link big north-south points). They have Frecciabianca and Eurostar trains going along the Tyrrhenian coast (western coast of Calabria). There is a modern railway there carrying trains up to 180 km/h. There are multiple fast trains connecting Reggio Calabria with Salerno, Napoli and beyond. No such thing as "no airconditioning": except for some regional trains, all others have it. You should have no problem riding services on that axis and connections to/from Cosenza or Catanzaro. Now there is a slow and non-electrified line along the Ionian coast (east). That line, going all the way from R. Callabria to Taranto, is painfully slow and has only limited service. AVoid it. If you are going to Sorrento, take a fast train to Salerno and continue from there.

Thank you for your advise. I will look further into traveling by train.

If your destination is Sorrento, I think you'd find it easier to take the train to Naples instead of Salerno. From Naples, you have a number of options for the leg to Sorrento. You can take the local Circumvesuviana train, which departs from the "Garibaldi" station, which is underneath the Naples Centrale main train station. Trip takes a little over an hour. Another option is to take an Alilauro hydrofoil from the Naples ferry port (which is called Molo Beverello). Trip takes 40 minutes. (You take a bus from the train station to the ferry port). http://www.alilauro.it/ Or, door-to-door but the most expensive, you can hire a private shuttle van. With a group of 7, this might be worth considering. .