The park is huge and serviced by many subway stops. As mentioned by others you can get one of a number of MTA system and/or map apps (I use "MTA Zero - NYC Subway" on Android), or get a paper map. You really should have a map for navigating the subway system when you visit NYC.
There's an app that shows you every subway line in the citt. Very easy to Use.
I walked as my hotel was in times square. It depends where you will be travelling from. It's near madison Ave and 42th st
Ask someone on ground
Thanks! Your answer is awaiting moderation.