Oil leak

It could be left over oil that is still burning up on the exhaust but you could also have another leak. If you don't normally work on cars then you will have to have this inspected at a shop. It's best to clean up the engine first and then run it and see where the leak is coming from. Just make sure you have enough oil. Use this link to find a good shop near you. https://repairpal.com/repair-shops Alex