Try to control your ISO setting. Fix it and don't let it be auto. The noise in #1 is quite bad. Try not to shoot directly at the sun, except for sunrises and sunsets. Use -EV or control both your shutter speed and aperture when taking sunsets. #2 and #3 seems to be overexposed at the sun and underexposed at the buildings. Nice try!

Keep on shooting and experimenting!