How does a person know where their body parts are located, (nose, mouth, etc.) without looking? such as eating popcorn without taking eyes off movie.

It's called "hand eye coordination" although the statement implies that you must be watching where to put your hands,  thats not always true. And because you have had the same parts your whole life, unless something bad happened or you're just caitlyn (bruce) Jenner.

Ichoose a as my answer

Cotton was the very first