Reallyyyyy dark doesn't describe much at all. I'd say you should play around with some settings and see how it all works out. Slow your shutter rate and up your ISO. Fiddle with this until you have your shot.
Photography is all about light. When you don't have any you can't really make much of a shot. Unless your flash is very powerful you won't be lighting up a landscape scene with it. (And when I mean powerful, I mean REALLY powerful, a hot shoe flash won't even come close. Generally, nighttime photography is done with long exposures on a tripod leaving the shutter open for long periods of time. However, the problem is that the longer you leave the shutter open on a digital camera, the more noise appears. A D3200 will really struggle to be open long enough to capture a shot like this. Furthermore if you leave the shutter open too long you risk overheating your sensor.
Alternatively if you have a lot of patience for trial and error you could try light painting the scene with a powerful flash light.