I can tell you a little about New York City, since I've lived there most of my life and even drove a yellow taxi there for awhile. The best way is to avoid the horrendous traffic and leave your truck behind. A handy campground to do this is; http://blackbearcampground.com/
It's an hour's drive north of the big city. But that would be in a perfect world.
It's far better to take the tour bus that leaves from the campground. Manhattan is truly wondrous, but go with a plan which I'm sure you would do for any other place you go. A neat way to get a feel for the city is to take the red open air buses that goes down Broadway from mid-town through Grenwich Village, China town and Wall Street to the South Ferry. You can hop on and off the bus route anywhere at will with a day pass. Discount tickets for the Broadway plays can be bought at 47th and Bdy at the kiosk.