Tim do you remember the name of the company? Where in Pompeii/Naples can you store luggage?
https://community.ricksteves.com/travel-forum/italy/amalfi-coast-day-trip
There is luggage storage at the major entrances of Pompeii, and also at the Circumvesuviana station at Pompeii Scavi. There is luggage storage at the Naples train station, but I have not seen it or used it. I'm a little confused, because someone staying multiple days in Sorrento and in Amalfi (or Positano) is usually not in such a rush that they have to see Pompeii along the way. But it's your trip and your travel style. Are you aware that some visitors spend 8 hours at Pompeii? I think it might be fair to say that the average is 3-4 hours, but I'm not basing that on real research. Sun and heat are a factor, as well as the uneven Roman pavement.
JR, I mean this in a nice way, not as a criticism, but you owe it to yourself to spend at least two hours with the Search box for this newsboard, and read at least 40 post replies. You are undertaking a common Italian vacation portion, but as you say, at the last minute. This board warns that Sorrento and the AC book up six to twelve months in advance. It's an unfair summary, but for the sake of being concise, SOUTHERN Italy is a bit of a third-world place, compared to Northern Italy. Everyone loves their trips, but transport and access are not like visiting the major cities of Europe.
Have you two been to Europe ever before?
I would not take a recent bride (made that up, based on your OP) to a hotel in the workaday modern city of Pompeii, facing the ruins or not, with little else to do, and not enough restaurants to walk to. I know someone who stayed in Pompeii will post to refute this, but I'm expressing an OPINION, not an established fact. Sorrento is a purpose-built, postwar Resort Town. Pompeii is not. You are, I think, trying to plan a major segment of your trip without background information like you might get from a guidebook, or substantial reading of this and other newsboards.
Have you looked at Google Maps yet? Do you know how far it is from Rome to Sorrento? Are you ready to pay 450 Euros for a three-hour-plus car ride? (Lots of medium-budget travelers here hire a car service from the [EDIT] Naples train station to Sorrento, probably around 120 Euros these days.
It's an advanced topic to "stay on Capri", but I'd comment that Capri is (to ME) much more attractive than Positano. I was glad to "see" famous Positano, but I had no desire to stay there after I saw the overpriced clothing and cosmetic boutique stores you can see in Rome, and the small, all-pebble beaches. I mention Capri mainly because it is so easy to get to from Sorrento. (October weather would affect ferries, perhaps. I was there in May.)
You don't have a choice about where to stay in Sorrento. You are going to have to take the tenth place on your list. I was late at six months, and had to take one of the 5-7 luxury hotels on the cliff of Sorrento. We could afford it, and in fact paid extra for a room with a balcony and a Vesuvius view from the foot of our bed. We also liked the fierce modern air conditioning at the Ambasciatori Grande. One parent company runs five of the hotels on the cliff. (Sorrento is built on a gulf-side cliff. I am NOT talking about the lower-budget hills on the mountainside that also attract bus tours. They can, legitimately, also claim a "view".