Not sure where you are in Canada - I'm in New Brunswick. I don't think your age is an issue. I had someone younger than you work on desensitizing my mare at the recommendation of my very knowledgeable trimmer. So word of mouth in small towns like is going to be everything.
As everyone said, of course you'll need to look into insurance. But I would also lean more towards you traveling to people's barns to work with their horses than keeping their horses at yours. I have never been comfortable with the idea of sending my horse away for training. I need to see the trainer work with my horse and know how to handle them myself as well. So you might start with that. My only other hesitation would be around the idea of people paying for ground work. While I am the first one to say that ground work is so very important, I find that most people just want to ride. So I'm not sure how much business you'd get just for ground work.
I think you might want to get known a little better too. 2,5 years is really not very long and a handful of horses may not be enough to convince people that you have a skill they want to pay for. Many horse owners have far more experience than that. But if you can keep working with people through your personal contacts, maybe you can negotiate something. Like you'll help with their horses in exchange for something.
Becoming a trainer is a long-term goal and I encourage you to keep working towards that, but it will likely take some time before you can have enough clients for this to even come close to paying the bills. Still, some people really have a talent for it, and if you can have a few success stories, you might just be on your way!