No worries.
Actually, the best way to start leaning, should you care to learn, is to just go out and try some software, much of which is actually quite good and also very much free. Blender is probably the most useful, though I personally have never had the patience to tame the beast's UI. SketchUp is almost instantaneously started... and then seemingly just as quickly inhibited/limited by it's own UI. Wings3D is also a free, open-source program, though I've never used it.
For a balance of functionality and useability, try AC3D. It'll cost you, but it's pretty cheap in comparison to a great many other CAD programs.
Personally, I've been tempted to give Silo a try, though I haven't had time to play with the demo... which only lasts for 30 days.
If you're interested in any of these but can't find what I'm referring to, please feel free to ask.