Permanent move from the UK to NYC. PRICES?!:)?

okay, so ive wanted to move to nyc for ages. and im sick of getting different prices all the time. I like want to know everything- how much it will cost to get from england to new york-(airfare, the green card etc.) how much i'd be paying for a 1/2 bedroomed flat-NOT in the bronx. how i get there? I have no relatives/friends in newyork, or any part of the states.Do i need qualifications? I dont have any criminal records, or anything bad. & would it be best to move there after ive been to university, or before i start&go to uni there instead. PLEASE give me as much information as you can!realllly appreciate it:)