For information on whether or not a visa is required and how to obtain it, go to the State Department's website: https://travel.state.gov/content/travel/en.html
Letter of invitation:
A letter of invitation may be requested using this online form.
Note that it may take several months to obtain a visa; we urge you to begin the process as soon as possible. It is the responsibility of the participant to make sure that all documents necessary for a visa are submitted on time.
Airports: If arriving by airplane, you will want to fly into one of the three major airports in the New York City area: J.F. Kennedy (JFK), La Guardua (LGA) or Newark, NJ (EWR).
Trains: Those starting from a nearby suburb can reach NYC by NJ Transit, Long Island Rail Road or Metro-North Railroad. Amtrak also offers comfortable, convenient service to NYC from cities near and far.
Bus:For some travelers, especially those coming from other East Coast cities, buses are an affordable and convenient travel option. New York City enjoys service from such companies as Megabus, BoltBus and Greyhound, as well as other local carriers.
Once in New York City, MTA Subways and Buses gives you access to trains and buses that travel to every corner of the City. Taxis are also a quick and convenient way to get around the city.