Just replaced spark plugs and wires and my car is still miss firing and I can’t pin point why and my old spark plug is oil covered

So I just replaced my spark plugs and plug wires and I'm still having a misfire in cylinder number 2 of my 1998 Ford Contour and it lacking getting up to speed I also noticed oil in the plug what does that mean

My car has 151135 miles.
My car has an automatic transmission.

– Just replaced spark plugs and wires and my car is still miss firing and I can’t pin point why and my old spark plug is oil covered