The first port is Santorini. I've been to Nice briefly, never to Cannes. We've been to Athens for two days, had a good time, some good food. We've been to Naples briefly. Some of these places we'll just debark and wonder about, like Cannes and Naples, no tour.
This is a larger ship than the one we did last in Asia. It's not the largest and newest. It's pretty easy to find a place to hang out that isn't crowded. I booked z larger balcony cabin on the 13th deck.