@TS while you're at it, also please take note that girls watching from the block are not looking in your direction while you're flashing at it
depends on what you want to achieve. we use a smaller aperture i.e larger F-number to get a greater DOF for landscape. however, when that happens, your shutter speed is slower. (small aperture = less light reaching the sensor for the given shutter speed)
your camera's metering screwed up the exposure. since you're in aperture priority, what you need to do is to use Exposure Compensation as mentioned by the rest of the bros and sis here. increase it to +1, then +2 and you'll see the difference.
at night, to get a good exposure where the subject is well-exposed, you need to slow down your shutter speed. since your camera's already on a tripod, perhaps you can try Manual Mode, use the same Aperture settings, while using slower shutter speeds each time to get different exposures. then, it's easier to understand how to get the exposure you need.
that being said, there's no magic settings for exposure. it depends on the amount of light and the resulting effect that you want to achieve.