There's no schools in Canada that offer a full course in gunsmithing. Also, don't waste your time and money on mail courses, because they are not that good. You should contact your local gunsmith and ask if he'll take you on. Ottawa has, I think, Gungo? The owner's name is Spencer, if I remember correctly? Or you can relocate? Marstar was looking for a gunsmith with training available about 1 year ago or so. Or check out Brownell's in the U.S (do a google search) they have a list of sevral schools that have full time gunsmithing courses in the States. Actually if you contact any older gunsmith still operating full time in Canada, I'm sure he'll be interested in taking you on, and maybe even sell you his buisness in the future?
All the best.