If your nifty fifty is actually the 35 f/1.8 DX (which is the DX equivalent of one), you should be very happy with the results. A true 50mm on a D3200 is definitely a bit tight, but both provide excellent optical performance (assuming your 50mm is one of the newer AF-S Nikkors - can't speak to any others), especially at night. The simpler optical formula and judicious use of aspherics lead to them being fantastic at night.
You should also get good results with the 18-55 if you keep it at 18-244mm, which does have an f/3.5 aperture and VR, but beware that you'll want to shoot it at f/4 or so or you can end up with some pretty bad veiling flare. Try your best to keep any light sources from hitting the lens, and use your hood if you've bought one, and you should be okay. For night scenes, you'll find that primes are far better, but lack wide angle capability.