2015 Altima-smoking at ignition

I had the oil changed in my 2015 Altima last week. Technician advised that oil was very dirty and recommended that I drive it for approximately 1000 miles and bring it back in for another oil change and let them clean oil pan that is also dirty. Now every time that start the car when the engine is cold, a large cloud of white smoke emerges from exhaust. This does not occur when engine is warmed up or the car has been recently driven. The engine has approximately 115,000 miles on it. The technician stated that he didn’t see any engine damage when the changed the oil. What could be causing the smoke and how do we remedy this?

Its condensation. It's always happened, you just never noticed before.