The most likely culprit is a valve cover gasket. They are a cork or rubber gasket, and prone to becoming squashed, torn, or porous. If you have an inline motor, you will have one. A V6 or V8 will have two. They’re right at the top of the motor, and if they don’t have too many things routed over or around them are not that difficult to replace. Another leak possibility is an oil pressure sending unit, which is usually somewhere on or near the top of the motor. It could be screwed into a cylinder head, usually but not always at front or back, or could be screwed into the top of the flange that the oil filter is screwed on. It looks like a stem with a hexagonal “mushroom” on top, with a black plastic center with a wire attached. If that’s your leak, the oil usually leaks around the plastic center. There’s no fixing it, it’s remove, toss, and replace. If the leak isn’t obvious, get a spray bottle of all purpose cleaner, spritz the oily spot, then rinse with water. Use an old rag to clean it if necessary. Then start the car and watch to see where the oil is coming from. Or, take it to your usual repair shop and let them do it. These two items are the usual suspects, the leak could easily be someplace else.