white smoke

I have a 2000 Focus ZX3 the problem is everytime I stop there is a faint cloud of white smoke from the engine. It goes from the engine to the vents inside the car and has a burning type of smell does anyone know what it could be.

could be engine oil burning off from a leak.have you checked for oil
leak possibly dripping on a manifold?

It could be a freon leak on your A/C if you had your unit on at the time.