2000 Chevy Metro...White Smoke?

I have a 2000 chevy metro, whenever i start it up after it’s been sitting for a little while a white smoke comes out of the back of it. Does anyone know why this is doing it and how much approx. it will cost for repairs.

If it only does it after you have been sitting for awhile, then it is one of two things.

Condensation forming inside the exhaust system. The white smoke (steam actually) will dissipate as the water inside the muffler and tail pipe evaporates. No cost.

Very early stages of head gasket failure. a tiny bit of coolant seeps into the cylinders while the engine is cooling down. The white smoke will only last for a few seconds (like one or two seconds) as it evaporates very quickly. Cost, much higher than above.