Complex drawing operations must be simple and convenient in tool selection. You can teach yourself CAD or attend classes. This is a very good learning method. First, you should be familiar with several common commands, and then simply draw a straight line, copy and other commands. Gradually start a slightly more difficult pattern, such as flowers.

If you want to master CAD drawing design, you must know how to understand CAD drawings. You need to know the labeling and dimensions of a set of drawings, and of course you need some geometry knowledge.