I just completed this cruise on the Voyager OTS a few weeks ago. You can purchase the shore excursions on the ship, the prices on the web site and on the ship are the same. As a first time cruiser, I suggest you use the ship's excursions. Some of the ports are quite a distance from the cities you would want to visit. For example, Rome and Florence are both about 90 minutes from where the ship docks. You want to make sure to not miss the ship when it departs, and if you are on a ship sponsored excursion, they will make sure you get back in time or the ship will wait for you.