There can be several reasons why the photograph is not clear.
The first thing is to check your focus. If you are using auto-focus, hold down the shutter button halfway so the camera can reset its focus. If you are doing manual focus, adjust the focus ring at the end of the lens so the image is sharp and in focus. The aperture setting will determine the focal length and what will be in focus.
After checking the focus, is the lens steady while the shutter is open? If you have a slow shutter speed, then you will need something to keep the camera steady. This is where a tripod will come in very handy. If you do not have a tripod, you can use almost any stationary item to keep the lens steady.