David, mastering CAD is a process, like everything else. You'd be surprised how much you can learn by simply trying. I wouldn't say I am an expert but I have used it, in many forms for years and work in both 2d and 3d. I haven't used it much recently but in the past have used it do design 3d roofing models for students training for our Carpentry skills competitions, in the UK, Europe and at World Level.