I studied CADD from a Technical College. I took it just because my goal at the time was to be an electrical engineer, I am a former electrician now i am a civil designer/technician. I hold several 2 year degree's and my primary diciplines are Architectural, mechanical, civil, structural CADD. I do mostly 2D drawings, but I also do 3D renderings in early stages of a project of helping our Civil/Structural engineers land propective clients. I hold a CADD certificate took 4 classes to get it and i love it! Glad i got into it. I also learn on my own get text books or just get on the software and just go do things to learn can't go wrong. I started learning AutoCAD in 2004 got my certificate in 2005 where I got into Civil engineering. I live on Civil 3D software between work and home just learning.  I have also like the Bentleys Microstation. Crashes a lot less and it is built on microstation. I dislike autoCAd for one thing: rather than come out with new versions all the time I wish they would make the versions they have better and more reliable sometimes. I try to stick with just using autoCAD products I have found that straying away makes for problems down the road. Easier to edit and keep up with your projects if you can keep all the people you work with familiar with the same software rather than a lot of diffrent ones. I am 40 years old I also write simple LISP programs for use in autoCAD to make it more user friendly to help lessen ou work for the company I work for. I am currently back in school for my 5th 2 year degree in Civil Engineering Technology to help me with my goal of becomming a civil engineer. I plan on finishing this degree up soon and hopefuly can find help with tuition thur my company to help finish a 4 year degree in both Civil and Electrical it is where I can do the most good. I hope these answer a few of your questions.