Hi Darrion,
This video was recorded in an older version of Blender. When 2.82 came out they completely reworked the fire and fluid simulations using a new system called Mantaflow. This tutorial is a little out of date now and harder to follow along now. The dynamic paint section of this video is still good though.
I recommend checking out a couple of videos on Mantaflow for a better understanding of the fire and smoke simulation.