Hi Janet, and welcome to cruise-chat.com!
We've cruised to Bermuda several times, mostly on NCL, in fact. On your cruise, you'll be in King's Wharf on the western part of Bermuda. It's not a bad location, but not in the middle of everything, either. Yet, it's convenient by public bus or ferry to beaches, the city of Hamilton (shopping!), the town of St. George (history), and many other attractions.
So -- my first piece of advice is to buy a 3-day bus/ferry pass that will give you unlimited rides. Last time I was there, this was payable in cash. These should be set up in one of the Tourist offices when you get off the ship.
Second piece of advice if this is your first time to Bermuda -- NCL offers (or used to offer) a wonderful 5-hour tour of Bermuda. If this is available on your cruise, I highly recommend it to "get the lay of the land." I'd also suggest doing it as early as possible.
Other than that, let me know what interests you and I can make some additional recommendations.