Shoot only "M" otherwise the camera will overcompensate in its attempt to make it look like daytime.
If you are doing a street seen, I would start w/ 1/30th and wide open aperture and then move the ISO to where the exposure looks good to you. bump shutter speed to 1/60 if you can still get decent exposures & iso below 3200. Always w/ IS switched to "ON" on the lens.
Starscapes 600/focal length (24mm = 25 seconds) max exposure speed. F4 is a good starting point, try to go further open and lower ISO and shutter speed to reduce the electronic noise created by the sensor and signal amplifier in the camera. on a tripod w/ lens IS switched to "off" (longer focal length and longer shutter times turns the stars into little lines i.e. star trails vs. star dots)
HAVE FUN!