Nikon L820 Pictures Are Blurred?

The more you zoom in, the more you magnify any shake of your hands or the camera. You need a faster shutter speed to get sharp shots when you're shooting telephoto. There's a reason behind this but you don't need to know it in depth (it's basically about angle of view). Just remember the 1/focal length rule: if you are shooting at (for instance) 50mm, you need a shutter speed of 1/50 or faster to get a sharp shot (the anti-shake in some cameras will let you go a bit lower, but apart from Olympus' version they're not magic bullets).

The L820 has a 35mm equivalent range of 22-675, so if you're shooting at the long end of that you need a pretty fast shutter speed to get sharp results. If you're leaving the camera on idiot mode (full auto, that is) then it's possible that the camera is choosing too slow a shutter speed. I don't think that camera has PASM modes, so you'll have to either use a tripod to shoot at the longer ends, or improve your shooting technique : use burst - the continuous high setting - because if you shoot multiple shots of the same scene, the ones in the middle are more likely to be sharp, learn to hold the camera steadier, etc.

get a tripod, the more you zoom in the higher risk of getting a blurry shot you have

tripod would solve all problems

Shoot with more light.