There are two discussions here - White smoke and Blue smoke - so don't get confused.

White smoke is usually fuel (too rich) or water (condensation or a bad seal). Whatch the level of the radiatior for clues!

Blue smoke is oil. Blue smoke after sitting means oil is leaking by a seal of some type - valve guides and turbo seals are a good guess. Blue smoke while driving usually means the damm thing is worn out and the rings are not seating very well. Watch the oil level for clues.

White gooey stuff in the oil or radiator means your mixing oil and water - which is "a not too good thing"