See if it's helpful. It seems that you need to get a job offer first. You may try to convince the Martial Art School to give you a job offer. You can apply for a work permit using this job offer.
If you have a job offer, your chance of getting a work permit is much better. This school, if it wants to help you out, could offer you a job as either an instructor, or a janitor. You may get a one-year temporary work permit, and you can renew and extend it after a year. You may want to get anything you can get because work experiences in Canada will help you earn points when you apply for landed immigrant status in the future.