I live on Long Island, and at times have to go in for business. I HATE NYC.
I loved growing up on the Island, but no long like living here. Wish to move to a free state. Just not in the cards right now.
Never mind firearms..
Knifes, don't carry one, if they see a leatherman clipped to your pocket (knife on the inside, clip outside showing), it will get confiscated and if they don't like you, you could get arrested.
Anything that remotely possible that could be open easily, if it doesn't have locked closed blade, they will consider a gravity assist knife.. it's insane what the kangaroo courts are putting people in jail for in NYC. Do some research online about knifes and NYC, and it's documented online.. even stuff people have bought in the city itself - they've gone to jail for. It's a numbers came, so they can claim they are making the arrests and getting the convictions.
If you are going to drive into NYC, research where your going , find parking garages with all day discounts, get in there before 6AM, park, and make sure your wearing great walking shoes.
You can see most of mid town / time Sq in one day if your not staying for a show.
If you want to see down town by the new tower, do it a 2nd day. From what I understand you need an appointment / tickets in advanced to get in, IIRC.
Others I've known have stayed close in NJ (even less self defense friendly), and take a bus service in and out.