Not much of a video. Doesn't explain the basic principles behind orthographic projection as applied to standard engineering drawing either first angle or the alternative third angle projection. A much more useful explanation will be found in basic engineering drawing text books or even google
https://technologystudent.com/designpro/ortho1.htm
https://www.youtube.com/watch?v=P4Abk1jzty4
With modern Cad 3D modelling the program does the work, its just a configuration setting, you can produce a first angle dwg without even understanding how it works. The understanding part becomes important in reading and understanding an existing engineering drawing