2000 Saturn SL2 Oil Smoke

I just bought a 2000 Saturn SL2 for $500. The seller said it ran a little rough but nothing major. I drove it, it has plenty of power but a little stutter and some engine noise. No smoke or smell out of the exhaust.

I got the car home and checked the fluids. Not a drop of oil. I add about two quarts just to check it out. Turn the key and I am lost in oily thick fog.

I am wondering if this could be a bad valve or piston ring, or have I just bought a junkyard special?

Thanks.