If your desire is to be an RHI check with OAHI. Certainly the college certificate courses at Humber and George Brown will get you started. Do yourself a huge favour, don’t give up your day job for this new career. It takes time to get established in this industry.
BTW I would also consider joining NACHI. We have great on-line courses including the “Defect and Recognition” course and most are FREE to members.
Mario gives good advice, I have been plugging away for almost 2 years and I am in no way able to go fulltime yet. It takes time to get established, this is a reputation based business and that takes time to develop. Best of luck.