Where are you staying? I also did the NYC marathon last year and doing it again this year-
Go to SoHo and pick a direction and walk-
Union Square
Greenwich Village
West Village to East Village
I really love Chelsea though- Chelsea Market is awesome and the surrounding area. Very easy to be around
Flat Iron District around Madison Park is also very beautiful but slow at night which can be very nice NYC photography
The Ghost Busters Fire House 8 is really cool but not much around it-
Time Square during Halloween right before the marathon is also amazing but if you walk towards Hell’s Kitchen, its gets pretty crazy in a good way through there as well.
Pretty much just walk outside in NYC, Also small is king and so is large aperture. Grab a combo that is good at high ISO and set your shutter to 250 at f/8. At night maybe f/4. The beauty of NYC is NYC- Don’t hid any backgrounds-