I shall try and answer your question with regards to how solo travel works (at least with us at Riviera) before moving on to perhaps suggesting a couple of tours that we run that may be of interest.
As far as itineraries go we do try and include a good amount of excursions and visits on our tours so that people do not feel obliged to purchase extra add-ons to be getting the most out of their holidays. Our included excursions are not obligatory and you are more than welcome to do your own thing should you so desire, either staying in the environs of the hotel, traveling on the coach to a destination with the group but exploring it independently, or striking out on your own one day (our tour managers are a great source of ideas and information that can help with all sorts of planning).
With regards to food on every tour without exception the first evening's meal will be included, as will a little drinks reception, so that you can get to meet your fellow travellers. From then on it varies from tour to tour, so you may have all dinners provided and the groups dine together, you may be free to choose where to have dinner yourself, or some combination of the two. Where there is no dinner provided the tour manager will provide a number of recommendations for dining out and will be only too happy to help book tables for small groups of travellers to dine together.
So you see there is a lot of flexibility as to how you spend your time on a solo Riviera tour: we can provide a substantial programme where most things are taken care of for you, or you can do your own thing with help from our tour managers to help you get the most out of your time - the choice is up to you.
As far as recommending a tour for you we have a number of tours to Italy departing in May and June, such as our Classical Italy tour, the Sicily: Classic and Undiscovered tour, or our Lake Garda and the Best of the Veneto tour for you. I would suggest you contact our highly trained reservations team (the number can be found on our website and our brochure) to discuss your preferences, days when you are free, and which airports you would like to depart from and they will be only to happy to advise you.
I hope this helps,