Hi Kathy,
Don't worry, you'll love it. I was enquiring with the editor yesterday about a previous tour, Amalfi Coast, and she explained that it merged with Sorrento as this was the most popular and remains so, so i can't imagine you'll have anything except an amazing time.
Everyone is nervous the first time but don't worry, you're integrated from the moment you get to the airport and normally on the first night there's a group dinner to get everyone talking and planning their holiday. Also, don't forget most people are using JY for the first time so you wont be the only one in that boat.
Thanks