Hi,
The best time for night shots is when there is still a bit of daylight to avoid inky-black skies. However, your digital camera will manage a better job of this than film so you will get away with it.
You could set the ASA to 16000 but I don't recommend it unless absolutely neccessary, so try 800asa. 'Auto white' should take care of the white baance but there are a number of artificial light settings you can try for varying results. If you aren't happy with the grain/noise from 800 asa then lower it to 400. However, the higher asa settings will help you gain a fast enough shutter speed to stop movement. You will require a longer exposure. I often took night exposures of 30-32 seconds with 100 asa film and got very acceptable results.
If you can't get a fast shutter speed then use a tripod.
Here is an example of a 30-32 second exposure with a film camera (on a tripod). I also used an 80B 'blue' filter to convert the daylight film for artificial light use.
The interesting thing with the picture above was how steady the driver stayed throughout the exposure. Likewise, the telling of whether your exposure is quite accuarate for the lighting conditions, is in how much detail you see inside the loco cab (this could be a shop window etc). Too much exposure and the detail would be washed out and, too little it would look too dark.
And here is a couple of handheld shots with my Canon 350D SLR. At 16000 asa.... White light balance was on 'auto'.
Trust that this helps.
Cheers.
BillEWS.