The problem with things like this is that there isn’t much of a way to help without actual inspection of the car. Something is leaking, yes. It could be oil, transmission fluid, coolant, power steering fluid - basically any of the fluids in your car. So you will have to take it to someone. But you should not take it in and specify what should be checked. The only thing you can do is take it in and describe what you described here. The most important thing is the specific location of this smoke - as close to exact as possible. Color and smell are also helpful. Stand over the car with them and directly show them. If they come up with a potential/explanation, make them show you directly.