Where to stay to visit Pompeii

We were thinking that Sorrento would be a good base.
I stayed in Sorrento and loved it as a base to visit Pompeii, Herculaneum, Capri and the Amalfi Coast. I visited both Pompeii and Herculaneum by train. Pompeii takes about 30 minutes by train, Herculaneum an hour or a little more. By car it appears to take longer.

How long do we need to see Pompeii
I stayed about 3 hours and could easily have spent twice that. I also think a guide would add a lot of value at Pompeii.

and is it recommended to visit Herculean too?
That's personal preference. Herculaneum is much smaller but still quite fascinating.

Edit: I just noticed that you've accidentally posted this in the "Montenegro" forum. If you repost it in the Italy forum you may get more responses.

We took the train from Sorrento, very easy. Stay in Sorrento.

You didn't say if you are on public transportation or have a car rental. Parking can be expensive in Sorrento or anywhere east of there. The point is that the commuter rail (Circumvesuviana) from Naples to Sorrento is perfect for either Herc or Pomp. And it's very cheap. Use the Search feature top center for more details on those two visits if you don't have a printed guidebook.

Because the Circumvesuviana require a change of trains in Naples, you should not stay in Sorrento if you have a flight home before 3PM from Rome (and even that's a little risky.) You may wish to reserve NOW the non-changeable, non-refundable Frecciarossa service from the same station in Naples that the Circumvesuviana delivers you to, because advance purchase is so much cheaper. You sill have to change in Rome for the airport train, if that's where you're going.

https://community.ricksteves.com/travel-forum/italy/herculaneum-and-pompeii-questions

https://community.ricksteves.com/travel-forum/italy/pompeii-and-vesuvius-69e8366c-1e75-4a14-a0bc-0677269492d1

Thank you for pointing out my mistake re: Montenegro - didn't realize that

A car in Sorrento?? sounds like a nightmare to me. Maybe stay in Pompeii? If you're going from there to Rome, I'd drop the car in Salerno and consider staying there, though it's awkward to get to Herculaneum. From Salerno you could visit Paestum and a buffalo farm before getting rid of the car.

Did you have a car on your first trip?

We spent practically an entire day at Pompeii, maybe close to 8 hours. It wasn’t the plan but we were absolutely fascinated. It remains one of my all time highlights of many trips. Not surprisingly I guess we opted to visit Herculaneum the next day as well and were glad we did, though we didn’t spend as much time there We stayed In Sorrento and took the easy train to both. Sorrento itself is a lovely town. We didn’t have a car so can’t offer suggestions. Safe travels

You will not make a mistake if you spend that time in Sorrento. We loved it and we would go back in a blink.

Sorrento will be a place you will never forget. From there it is an hour train ride to Pompei. You can visit Capri and see the blue grotto. Or just get lost in the many small streets in Sorrento.
And if you like to try to eat pizza in a local restaurant.... close to the train station is a restaurant called "pizzaria di franco". it has benches and the pizza is served on a metal tray with baking paper. plastic cups for wine. The ceiling is full of parma ham. But their pizza is the best I have ever had..... My favourite, pizza? Primavera, parma, arugula and parmesan...
Oh my, now I want to go back!