Right now I’m not freelancing as much as I have a steady job. But as a freelancing artist you just have to get your stuff out there, e-mail relevant companies with your portfolio along with a polite and professional sounding letter. I haven’t freelanced for long or much yet, but in my experience finding/getting the jobs is at least 60% of the work.
So basically get your stuff out there and be good enough to hook some clients, the more job’s you have under your belt the easier it will be to score new gigs.
I didn’t go to art school, not really, but don’t use me as a template, just do whatever is necessary to increase your workmanship. If you’re truly interested in your craft, then you will find ways to learn!