These are very good example to start learning Engineering drawing
https://grabcad.com/questions/tutorial-14-3d-engineering-drawing-1-auto-cad https://grabcad.com/questions/tutorial-15-3d-engineering-drawing-2-auto-cad https://grabcad.com/questions/tutorial-13-engineering-drawing-2-making-progress-in-autocad-with-this-drawing https://grabcad.com/questions/tutorial-16-for-beginner-engineering-drawing-1