Why is there Thick white smoke coming from tail pipes?what could this be?

It last until after its driven a while...will I need to put in a new catalytic converter???and the fluid you are talking about is that one of the fluids they check when you get the oil change where they check everything cause he told me all my fluids were good and full...the brake light came on about three days after this started happening...and after oil change...

About how long does it last? Does it only happen the first time of the day it is started, or every single time you start it that day? Also, yes, they are supposed to check it. I know its not related to the smoke. Sometimes it could just be that your pads need to be replaced, and maybe the fluid was at a correct level when you were there, but dropped afterwards from your brake pads becoming low... So you may need new brake pads. It could also simply be an ABS unit that has failed.. So, I'd get that checked whenever you can.