Are the Circumvesuvana trains between Pompeii and Sorrento regional trains? I attempted to purchase tickets online, in advance, however, there were no seats available. Will I be able to purchase 2 tks at the train station when I arrive at the end of July? Same thing from Sorrento to Naples?
Skim down below to the posts that describe the Circumvesuviana. It is an independently operated commuter service, very basic:
Other than Naples, tickets are often at the nearest news stand.
Yes, they are on a separate regional system, so you can't buy tickets through Trenitalia. You can buy them at the station ticket offices, or from nearby tabacs or newsagents. Expect to pay cash.
It is a Naples Metro that leaves from the far end of the train station and you buy your tickets from a teller before going downstairs- no assigned seating pack as many as possible per car.
We have taken it several times, however, if I remember correctly, every ticket is a "day" ticket, so I believe that you can get off at Pompeii and continue to Sorrento or return to Naples. Sorry if this is a little foggy, but all of our use was Pre-Covid.
Be prepared to watch your wallet, purse, phone and so forth as it's a pretty gritty ride.
Don’t forget to validate
Tix are cheap
Info on the Circumvesuviana commuter train; operates between Naples and Sorrento with stops, including Pompei Scavi - Villa dei Misteri, along the way.
https://www.sorrentoinsider.com/en/naples-to-sorrento-train-schedule
As said above, it isn't operated by Trenitalia, and yes, you buy tickets at the train stations it services. Yes, you'll easily be able to buy tickets when you arrive.