When I mount the lens the camera asks me to set the aperture to the lowest setting and lock the ring. When I lock the ring the lens works but the auto focus is non existent. The seller on eBay that I bought it from stated it was an auto and manual focus lens for all DSLR Nikon's. Any thoughts?
Your lens will work on your camera, but it will need to be manually focused. The seller may have technically been correct while intentionally being a bit misleading: it is an autofocus lens and it can be used as a manually focused lens for all DSLR Nikon cameras, but it can not be used as an autofocus lens on all DSLR Nikon cameras.
Your lens does not have a focus motor. It can autofocus only with Nikon cameras that have a focus motor in the camera body. The D3x00 and D5x00 series, along with the older D40 and D60 do not have focus motors in the camera body. For more, please see Which Nikon DSLRs have an autofocus motor in camera body?
I believe that only the newer versions of the Sigma 70-300mm F4-5.6 APO DG Macro have the built-in AF motor to make it compatible with with your D3200. Photos of this lens show it has no aperture ring.
The fact that you mention aperture ring tells me you must have an older version without the AF motor.
Can you return or exchange the lens?