If you're coming ashore in Aruba by cruise ship, you can find several cheap and easy things to do right at the port. I took a wander during my last stop there so that I could compile a guide for you outlining what I found.
You can try a few of these options when you come to Aruba on a cruise and decide that you don't want to pay for an expensive excursion. All of these options I found within a 30-minute walk from my cruise ship.
The area is filled with restaurants and shops, as well as where you'll find the historical, numismatic and archaeological museums.
I recommend stopping by Iguana Joe's for an appetizer and a beer or seeking out Lolita's Sandwiches. Pull up a stool at this small open-air serving counter (on Havenstraat, one street behind and parallel to L.G. Smith) for a Balashi beer or two and an empanada.
Thanks for reading!
Enjoy you time in the island paradise.