white cloud of smoke from exhaust only upon start up?

Hello,

There are several reasons why you could get white smoke during startup.
One of the common causes for these vehicles is leaking intake manifold gasket.
It can also cause if there is a leak in the head gasket. The leak can be too small to have excessive amount of coolant for it to have white smoke all the time but as the vehicle sits overnight or a period of time it will have some coolant that crates the white some on start up.

https://www.2carpros.com/articles/white-smoke-or-steam-coming-from-the-exhaust-pipe

There is a test that you can be done to see if the head gasket is leaking. It uses a chemical to detect combustion gases in the coolant.

Here is a helpful video on the test:

https://youtu.be/5zpNjYmmiYY

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.