I always tell people to ask themselves a series of questions and answer honestly if they are moving to New York City.
Why are you moving to the city? If you are coming as an actor, you may want to check out the various regional theaters that are doing work vastly superior to what is on Broadway. Get some credits under your belt before attempting Broadway.
What has influenced you to move to the city? If you have a dream that it's going to be like Sex & the City or Friends, you should rethink your move. TV shows never show the reality of the city.
Are you a loner? The city can be a difficult place to make friends. Can you survive without friendships for awhile? Can you think of ways to make new friends? Church, social organizations, volunteer work?
Are you coming with someone? Is their commitment to life in the city as strong as yours? Will they bail on you after two months?
Can you deal calmly with roaches and mice? Do you freakout at dust? The city is a dusty place, opening a window means you'll be wiping down everything in your apartment. Your apartment will have roaches and/or mice. This is part of the New York landscape.
Can you deal calmly with noise and confusion?
Do you have a decent amount of money saved up? I would recommend at least $10,000. New York City is very expensive and the job market is thin at the moment. Have you thought of ways to economize until you get on your feet?
If anyone ever tells you that you put too much Parmesan cheese on your pasta, stop talking to them. You don't need that kind of negativity in your life.