Nicky,
There's NO city like NYC. You'll love it!
That being said, I am not from NYC but have been there a few times. A couple words of advice:
When you walk down touristy area of Broadway, crowds will be enormous. You have to walk at a rapid pace AND whatever you do, don't stop to tie your shoe, or light a cigarette in middle of the sidewalk, you'll get run over and some dirty looks.
You have to step under a doorway and out of the flow of people walking. Ha ha
Be careful crossing the street. I know. Sounds like a mother hen right? Ha ha. Maybe it's cause I'm in laid-back California, but NYers drive very fast and aren't afraid to honk their horn or yell at you if you cross the street incorrectly.
Enjoy your trip. I am sure you'll have a great time.
TIS