I liked art, drawing and painting in school. Did gcse, a level, foundation then went to do a 3d design degree but that ended up not what I expected. Thought bugger that and went for a fine art degree instead. Never really thought I'd make it as a artist - and I didn't, not too good at selling myself. However I did do alot of cad work and 3d rendering, now I'm a Naval Architect.
Get as many qualifications as you can, cause everyone else has got them, also try to use as many methods and programs as possible, then try to get some work experience/ internship somewhere. And have a bit of fun while your doing it.
One thing I found interesting was making a computer model of my house complete with furniture etc - taught me alot about the program I was using at the time [3d Studio Max] and a lot about textures, how to apply them and animation.
If you go to college uni etc try to get hold of a copy of there educational licenced cad software for you to use in your own time.
Good luck.