If you're on the lower west side where the Intrepid is, stop by Chelsea Market for some good food and take a walk on the High Line.
Also, go to a deli. Our favorite is 2nd Ave Deli. On 33rd between Lex and 3rd, midtown.
FWIW, I've never felt unsafe in NYC. That includes traveling to the Bronx at night to see the arboretum...
The aquarium at Coney Island is outstanding
