If you lived near me I could use a helper that wants to learn.
Try to get a job at a local body shop. You'll probably start out just doing sanding and grinding but you'll learn a lot by watching how they do things. You need to know the basics before you can start doing custom work. If you start a project while working at a body shop the crew will probably help or at least offer helpful advise.
Custom cars are scarce in Canada I have family in Nova Scotia and Ive never seen a rod or custom when I'm up there. so you might need to move to Southern California to make a career out of it. Maybe a larger city like Toronto or Quebec have enough population to support a custom shop.