First off, you are extremely young. To be moving to such a city is a HUGE deal. You may not be thinking that, but it really is.
First off, NYC is quite costly. The standards of living are quite high and it's nothing like life in California.
People indeed are more bold and rude (just my opinion since I live in Texas). Walking through the city (specifically Manhattan) is like a human maze. You have to keep moving or else someone will run right into you. It can be very overwhelming.
I am planning (was actually) to move to NYC as well. PLEASE PLEASE POR FAVOR, visit the city FIRST
. You have to get some sort of feel for this type of city before you literally move.
Also, you will need lots of cash prior to moving. You simply cannot move to NYC without a good chunk of cash (I mean thousands, unless you want to live on the street or something). I'd check out Craigslist to look into places to live.
Also, consider living upstate if you can. It is much cheaper and less crazy (in regard to the city life). I love upstate NY (Westchester area), but to get to the city is a serious drive.
Please keep these things all in mind. Without many months of planning and budgeting, this would be pretty crazy papa.
If you have any other questions, just ask. I'll be doing the same thing sooner or later!