Hello! You are actually in pretty good shape for going to Yankee Stadium. I have not gone there yet, but when I looked at Google Maps, I was surprised to see how close it really is. The George Washington Bridge is the only practical way to get across the Hudson River at that point, and by car you will have to pay a toll of around $12.50 to $15.00 dollars. At least coming back across is free. I drove around New York City in February on the weekend and traffic was pretty heavy most of the time, so you would just have to allow for a lot of time by car. I would ask the hotel if they have a shuttle to the Stadium, but if not, I believe you would have to take the bus, or Taxi. You would just have to ask the hotel where you would pick up the bus. For the Bronx Zoo, it looks like you could take the subway from Yankee Stadium south to the 149th Street Grand Concourse, then back north to Pelham Parkway and from there taxi to the Zoo. At least the Stadium and Zoo are both relatively close to each other. Now all you have to do is take the subway south to Midtown Manhattan where you would find many tourist sites like the Empire State Building which is around 34th Street. Time Square is about one mile to the north. Just be ready to explore. Central Park is absolutely beautiful and the subway is very convenient and fast. My daughter just moved to Manhattan and has been taking the subway all over the borough and just loves it. Have a safe and wonderful trip and I hope you enjoy New York as much as I always do!