http://www.airsoftcanada.com/forumdisplay.php?f=37
Team page for Ontario. Find a team and contact them. You can usually tag along for a game and get a loaner gun then see what you like. You can also get AV'ed if the team has an AV rep or if you go to a larger (20+ person) game.
Keep in mind though that there was one incident of a guy getting turned off of airsoft cause he tagged along with a WWI/II re-enactors team and the guys playing were kind of "elitist" in the requirements of kit and whatnot. If you do like that kind of thing then it's all good but each team has a different goal/purpose. Some may be milsim oriented, some are a "boys Friday night out" type of dynamics, some may be re-enactors of Vietnam/WWI/WWII/etc. down to the socks and shoelaces.