Is it true that new yorkers are not friendly?

I am from miami, florida. i always wanted to go to new york ever since i was ten years old. Hopefully, I will go in the next two month for thanksgiving weekend. how i heard that new yorkers are not friendly? My sunday school teacher told me that her daughter went to live there for two months and one day she said good morning to someone and they just look at her. She didn't make any friends. So she move back to florida. Then it was this girl in my sunday school cl, when she move there from jamaica, she stayed there for three months and she didn't like it. She also didn't make any friends so move to florida. I am myself not that friendly either but i want to know is that true? I would love to go to new york. It always been my desires.