Why my car will start up but not drive

Ok so I was driving on the highway and my van started running funny not wanting to pick up speed. So I got off on the next exit which was a half a mile away. Wen I got off I stopped at the red light my oil light came on and my van shut off. I pushed my van out the way I noticed a puddle of oil in the street. I went and got got 2 quarts of oil and put it in it turned over but wouldn't stay started. I went bk hours later and it started but it was running really weird and shaking so I cut it off. Do I need more oil or is it something more?