How to fix an auto-focus problem on my Nikon D3000?

I've recently noticed that my Nikon D3000 is not auto-focusing, as it normally does. Typically, the lens will continuously rotate in order to focus, before the shutter is allowed to close. I also recently purchased a lens kit off of Amazon, which contained 3 Polaroid lenses, with adapters so that they would fit a Nikon SLR. I'm not sure if these lenses and the adapters may have contributed to the problem. Is there a way to fix a problem with the auto-focus, or simply manually focus through the camera's settings?

What type of lens did you order? If its an AF lens, it won't autofocus with your camera. If its a manual focus only lens, it obviously won't AF with any camera. Your 3000 will only auto focus with AF-S and AF-I lenses.

You usually can't autofocus if you're using non-Nikon lenses with an adapter.
Also, even if you use original Nikon lenses, only AF-S lenses will autofocus on your D3000, because it doesn't have a built in focusing motor.

"3 Polaroid lenses"? I don't know of Polaroid brand currently making anything compatible or useful. If you mean polarizing filters, why 3 instead of one 52mm filter to fit your 18-55mm kit lens?

If you bought a polarizing filter, that could be the problem if it is a linear polarizer. Linear polarizers can work just fine with contrast detect autofocus, which is used in live view. Your camera does not have live view. To be compatible with the phase detection autofocus of your DSLR, you would need a circular polarizer, not a linear polarizer.

The lens kit that you purchased was a set of tele or macro add on lenses wasn't it! Take those off the lens and it should work fine.

I don't know the background tech, but certainly on my Sony's the lens and camera talk to each other regards setting the focus. Add on a tele or macro adapter lens and AF is either very slow (because the suggested focus is different from there the lens electronics expect it to be) or totally non existent!

*Sony refer to this as ADI.