When I was 16 I had a push bike, like all my mates. Then we turned 17, one of us got a Vauxhall Viva, someone else got an Allegro. I got my first car when I was 28, cos you don't need one in London so much.
In New York the public transport is good so you don't need a car either, certainly not in Manhattan. But if you do, I'd get something from rent-a-wreck cos you can't go over 30-40mph as the traffic is so bad. MUCH worse than any UK city!
So my advice is, save your money, wait a few years, move to Florida or the midwest, THEN buy a TT where you can enjoy it properly and you have the driving experience cos whether it's an NA or TT you DO need proper experience, not JUST the knowledge of 'how to drive'.