When I was 14, I had an idea for a novel but never wrote anything. I'm now 24 and just finished participating in National Novel Writing Month (nanowrimo.org) where I wrote a 25k word "long outline" of my novel.
I'm now expanding and editing my novel. I'm very pleased with my plot and would like to do a good job with it. However, I lack experience writing and would hate to ruin an idea I've become so fond of by making it the first thing I write (and therefore terrible).
Should I write something I don't care about in order to "train"? Will writing my novel ruin it? I am interested in much advice.