The Mill is building in Survival Beginnings.
A mill is a very useful, simple structure used to turn Wheat Bundles to Flour, which can be wet with a water container and turned into Dough. This is used to make create most (if not all) of the more effective foods in the game, namely bread.
To create a mill, you need 3 wooden segments. Each wooden segment can be created with either two tree stumps, or a single large one.
It is possible that the turbines attacted to the mill will glitch and stop moving/ move slower. But you don't have to worry, the mill will still function properly.