I've been to aruba many times.
The bus depot is right in town, Orangested, get the bus (just ask, some one will help, with which one) to eagle beach. Beautiful stretch if beach.
Or get a cab and arrange a time for them to pick you up.
If time allows we stay for the sunset, then head back to ship.
Food and drink in Aruba is very expensive, I take a snack and drinks with me in a cool bag.
The bar there on Eagle beach, across from Amsterdam Manor, has a happy hour about 4 or 5pm I think.