White smoke coming from my tailpipe

The other night I noticed white smoke coming from my tailpipe as I was at a idle along with a faint burning smell. I went on YouTube and according to the information I found I have a blown head gasket. However, I am not using any oil or antifreeze. The car idles fine and drives well. Needless to say I am confused because it does not overheat either. I looked up additives like stop leak and engine enhancers, but I am afraid to put anything like that in my car. I purchased the car September 18 and the engine has already been replaced. I love my car but cant afford a head gasket job. Please help