Solution
Does the camera move when you press the shutter button?
Be careful not to move the camera when pressing the shutter button.
At night and in low light environments in particular, the shutter speed is slower than normal. Take measures such as using a tripod or remote controller (sold separately) to keep the camera steady.
Have you moved out of focus range for the target subject?
The focusing distance from the lens to the subject varies depending on the lens you are using. Check the lens you are using, and adjust the distance from the subject to the lens.
Is the AF point in the viewfinder on the subject?
The camera uses the AF point in the viewfinder to focus on the subject.
If the composition of the shot prevents you from setting the AF point on the subject, use focus lock.