If you were to take photos of scenes at night, a sturdy tripod is an absolute necessacity because you'll be using a lower shutter speed due to low light condition and also stopping down to ensure good depth of field.
There is no one setting for all scenes. You'll have to experiment yourself but a guide to start off with would be about ISO 100, aperture of f/8 or f/11 and shutter speed can varies from 8secs to 20 secs. Do note that timing is important and 19:00 to 19:30 would typically be the good time to take your photos, depending on the time of the year. I usually don't bother with anything after 20:00 because the sky would be completely dark by then.