When you take a photo of Moon with most cameras, your image will look like the one below. You might have seen nice photos of Moon by other photographers so you will blame your camera or yourself for bad photo you got.
Let me tell you that it is very easy to take beautiful moon photos with any high zoom camera.
Click on SetUp options on your camera and find out Metering set up. It may come up as Metering mode. It will have few entries like Evaluative/Matrix/Intelligent, Center-weighted and Spot. Most cameras by default have the first value. They are set in intelligent/Evaluative/Matrix setting. In this mode, the camera try to be intelligent and measures light in the whole scene. As most sky is dark, the camera gets into thinking that the frame is dark so it tries to get in more light. This causes the Moon to be washed out.
Set camera metering mode to Spot (icon with a dot in the center). Then keep the moon in the center so camera will meter light off of the Moon. This will make camera think that there is good amount of light so it will try take in less light. The result will be a stunning photo of the moon, as shown below.