Set ISO to auto.
Set the D50 to aperture priority.
Set the lens to f2 or f1.8.
Time your breath so that you neither inhale nor exhale as you press the shutter ... a common error in beginners is breath induced shake. If you want see an example just point your finger at something and watch how your finger bobs as your breath. Now hold your breath to the count of 3 while you point.
Press the shutter using ONLY tour finger. Another common error in beginners is squeezing with your whole hand. This also induces shake into the system.
Tuck your elbows in, and if feasible lean back against a pole or other sturdy immobile object.
The lens will make an exposure in very low light, it is the photographers job to make sure the camera is as stable as possible.
LWW