You have gotten good advise. Enjoy NYC. I live out in the 'burbs now, but grew up in Brooklyn. What you are hearing is true, NYers are very friendly people. They might come across as direct and abrupt, but if I was ever in trouble, that's where I'd like to be.
Be sure to go to Chinatown to eat, and if you like flowers, go to the Bronx Botanical Gardens. When you are done - go a few blocks over to Arthur Avenue for the best Italian food this side of the Atlantic.