Hi Jane
Welcome to the Community! You've picked a great trip for your first JY adventure. I did it in September 2015 and would happily go back- it's a super itinerary. The great thing is that the Hotel Palma where you are staying is right in the centre of modern Pompeii town and only a ten minute walk from the gates of the ruins (out of the hotel door, turn right to the cathedral on the corner and then right again and the ruins are straight ahead down the main street off the town square). You'll have plenty of time at the ruins with your local guide (fingers crossed that you have Laura who is absolutely brilliant) and she will leave you there to wander at your own pace when the 'official' walking tour is over. You also have some free afternoons/mornings during the tour, depending on how many of the optional excursions you are doing, so you have time to go back to the ruins and walk around on your own if you wish.
In terms of maps or guides, personally I got a Lonely Planet from Amazon before the trip but, on the main street en route to the ruins, you'll find the local tourist information office who are really friendly and helpful and have loads of maps and books to choose from. On the same street, you will also find a fantastic family run gelatoria & bakery called De Vivo which is well worth a visit or three 😛
If you haven't already booked it, I would thoroughly recommend the optional excursion to Herculaneum which is smaller and more compact but much better preserved than Pompeii itself. Personally I preferred it - it's very atmospheric.
Finally, just a couple of tips - take very comfortable walking shoes (because the paving at the ruins is very uneven), a hat because there is very little shadow at the ruins and it can get very hot in September and a water bottle (which you can safely refill from the public fountains on site).
Have a super time - happy to help if you have any other questions
All the best
Mandy