The Carnival Sunshine does a variety of itineraries and cruise lengths, with a five night minimum. My media sampler cruise was only two nights, but I did get to visit Freeport, which was a totally new destination for me. I've been to Nassau more times than I can count, but Freeport's an island I've always passed on my way to somewhere else.
When you go to a new destination on a cruise ship, the best way to experience it is by booking a shore excursion. You can set up something on your own if you know the port very well. Otherwise, I recommend leaving it to the cruise line because that gives you several advantages.
First, the cruise lines vet the vendors they use for their shore excursions. They don't want their guests to be unhappy, so they won't send you off for a bad experience.
Second, if a ship-sponsored excursion is late getting back to the ship, it will wait for you. If you do an activity on your own, you'd better be back in time for sail away. Otherwise, you'll be standing on the dock watching the ship pull away.
Carnival kindly allowed me to try out their new Freeport beach excursion. The photos will give you some idea of what it's all about.