If your 18 there are several places to play in and around Toronto.
The first one that comes to mind is TTAC3 http://www.fightingartscollective.com/fact/main.cfm
Brian, the owner can get you age-verrified which will open you up to the classifieds here on the site.
That being said, there are many other, both indoor and outdoor places to play. Most are paintball fields, but a few teams have private fields on Farms or woodlots