Flight
Any of these three airports are good to fly into.
Train
If you are traveling from out of town by train, Grand Central and Penn Station are where you want to arrive.
Travel Note
There are plenty of ways to get to the venue. Taxis, Ubers, and Lyfts are excellent car options. If your hotel is in New Jersey you can take the PATH Train's Journal Square line to 23rd St in NYC. Subway stops that are close to the venue include the 1, C, and E. However, keep in mind that the subway stops are about a 15-20 min walk from the venue. There is parking at the venue.
Travel Note
It is easy to find hotels in New York. You can also find Airbnbs. Hotels in Manhattan can be expensive so you could consider finding a hotel or Airbnb in New Jersey. Jersey City and Hoboken are great towns to check out and are close to the Path Train which is a quick and easy way to get to the wedding venue.