Where Can I Find This?

Where can i find a USB cable for a
Mercury CyberPix S-555V Digital Camera
My Dad purchased it for me on sale but it did not come with USB cable it was suppose too but it never, would they sell them at the store where he purchased them?

They should sell them at that store, but you could also call or email them, because if it was supposed to come with the camera, then if you requested it they should ship it to you. As a last resort, visit the brand's website.

try best buy or circut city

Try Radio Shack!

The first thing you should do is return it.
It's a cheap, off brand camera that frankly, is not competitive on features, performance or image quality with the many fine products from major manufacturers.

it was nice of your dad to get you a camera, but he didn't select wisely. (sorry dad). For the same price, you could pick up a Fuji F20 (with a $30 rebate) and have a truly high quality camera.