You first need to determine the cause of engine light on by getting the codes read. Leaking oil through valve cover gasket is a different issue, unless you have the +1qt oil indicator on, if too much oil has been lost. If the valve cover gasket is new, perhaps your oil filter housing gasket is leaking, not your valve cover gasket. You can try to clean wherever you see oil with a rag, and then run the car to identify the source if you can.
A specialized german car indy would be a good choice to get the engine codes read and to diagnose the real source of leaking oil.