Nikon d3000 camera lens?

My photos aren't coming out that clear and vibrant. Is it my camera, a setting or could it be the lens?

Hard to say. If it is a cheap lens, it could be the lens. But it could also be a setting. Are you using the 18-55mm lens the camera came with? If so, it is a pretty decent lens, so that is probably not the issue (unless it was damaged).

Could be your skills.

Sign up for a free flickr account, go to privacy options and set exif to visible. Upload a few that you're not happy with and post the link here.

It's almost always the person behind the camera. Unless the lens / camera are damaged.

What are you trying to shoot?

Cameras benefit from having a lot of light with which to take pictures, for both clarity and vibrance. A single desk lamp isn't going to cut it. Indoor shots are best taken with flash heads, or high wattage continuous lighting.

If your photos look vibrant on the camera's LCD screen, but less so when transferred to your computer, that is entirely a photo editing software issue. (The camera LCD's design also exaggerates vibrance and brightness.)

If you are shooting outdoors in bright sunlight, and the photos still don't look vibrant, then yes you probably do have a malfunctioning camera.