Well, generally, what you'll find at Walmart/Canadian Tire is NOT considered "airsoft". They're basically cheap and crappy toys that are useless for any real airsoft games. You'll also find Crossman and the like, but that's not airsoft either.
And note that you have to be 18+ to buy airsoft in Ontario, no exceptions. If you ARE 18 however, welcome. There is a link in the top-right to ASCA, a Toronto-based/online store where you can buy all of the latest and greatest airsoft guns and accessories. The only "catch" is that you must be verified in person before you can buy. But if you're making legit purchases, it's not a "catch", is it? $20 off your first gun for being verified even.
And there is a FAQ forum with plenty of useful stickies like a newbie guide. It would be wise to read that stuff and get any "stupid" questions you have answered right off the bat. You'll find that asking the obvious without doing your research (and sometimes even with) isn't tolerated here.