Is CAD 2D drawing difficult? I want to study for 4-5 nights. Can I learn basic 2D painting?

If you have the basis of manual drawing (you have studied mechanical drawing and can draw correct drawings with pen drawing), it is very easy to learn CAD software, and a good teacher can get started in a few days (improvement, skills come from practice and summary). If you don't have the basis of mechanical drawing, don't learn CAD for the time being. Learn mechanical drawing first. This is much more difficult than CAD. Many friends have studied CAD in the training class of computer school, but because they can't draw mechanical drawings (which are not taught in general computer schools), the drawings drawn are full of mistakes and are laughed at by experts. Such drawings are worthless at all. I hope it works for you.