Just start attending events, smiling, and introducing yourself to people. Make sure you are not shy about asking for what you are looking for. For example "I'm just figuring this startup thing out. I think I've got some great ideas but I don't have any mentors. If you know of any one I could talk to that would be great."
http://startup-ventures.meetup.com/cities/us/ny/new_york/
Just start attending events, smiling, and introducing yourself to people. Make sure you are not shy about asking for what you are looking for. For example "I'm just figuring this startup thing out. I think I've got some great ideas but I don't have any mentors. If you know of any one I could talk to that would be great."
Good luck!