I'm sure they have one in Toronto it is a large enough city but at least here in the US in order to register to gain admission you have to submit documentation proving that you own a greenhouse/garden center, nursery, ect or are part of an educational institution with a focus on horticulture. I guess what I'm trying to say is not just anyone can register and walk right in at least here in the US. Canada might have a different registration process.
The big one here in the US, at least on the east coast and mid west, is called
Cultivate. The last time I attended was back in '16 but because it is a long drive to Columbus OH I cant make the trip every year. When I was there it seemed that the focus of the show had shifted away from smaller production greenhouses like mine to large scale operations so I don't know if I'll go back.
Anyway, feel free to PM me anytime you want to ask a question or just shoot the shit about plants. I will tell you though that my focus is not on Cannabis production but on annual, perennial, and woody shrubs with a concentration on flowering annuals because that is what I specialize in growing and selling.