First we need more info. As was posted before take mpics from under the motor so we can see if it is leaking and where from. Then pull the PCV valve and see if its crusty. Then ya gotta check if it smokes at cold start up and when going WOT.
Could be a $5 PCV valve, could be $100 worth of gaskets, could be a $2000 rebuild. Just dont know without seeing it. "Its low on oil" dont help us to try and diagnose the problem.