What causes white smoke to come out of tailpipe?

The white smoke coming out of a tailpipe is called steam. It is caused by water leaking into a cylinder. It can be caused from a blown head gasket letting water from your cooling system leak into a cylinder. When the gasoline and air burn, it makes the water in the cylinder turn to steam. The steam goes out your tailpipe with your exhaust gases. If you do not keep your radiator full, you will blow your engine. If you do not get it fixed, It will ruin your lubrication system and ruin your engine. Hopefully, you are in a position to make car payments.

Can also be moisture trapped in the exhaust system if you make too many short trips and never get the entire system up to temperature.

Blueish colored smoke would be buring oil, caused by failed seals or rings. Black or brown smoke is gasoline. caused by too rich a mixture.