The sad fact of the matter is traditional raves tend to have club drugs (X, Molly, dmt..ect) heavily associated and easily accessible at them. Of course that doesn't mean you shouldn't/can't go to them, but most raves are typically 5+ hours, so If you do go I'd recommend a combination of some type of non-drug energy that is easily accessible to the blood stream (energy drinks, coffee...ect). Also, friendship is not typical magic there. Music is magic, music is life.
As to how you'd find out, go to clubs, typically they will have dance nights, if they don't you can ask around. Also, there are good forums out there associated with raves, google is your friend, and you can typically find information about raves happening in your area. A good amount of raves typically happen in warehouses and industrial areas.
Hope I helped answer some questions for you, NY is a big place and it won't be hard for you to find something. Have fun, be safe, and stay hydrated.
Also, I'd recommend going with a couple friends, until you get the feel of it, raves are very social events.
(P.S.- you will be tired afterwards, so keep that in mind when planning.)