I flew to Canada in July, and I had only a passport, and no Visa. For United States citizens, you can stay legally up to 6 months without needing to apply for any visas. I had no trouble at the border, I simply presented my passport and told them what I was doing in Canada. If you aren't a US citizen though, you'll need to apply for a visitor visa. I don't think they take long. You say what you want to do, how long you want to stay, and prove you have funds to support yourself and plan on leaving at the end of your legal stay. Then pay the fees, and you'll probably have it in less than 2 weeks. When is your flight? I'd postpone it and be legal, as if you are unsure, Canada won't feel bad if they don't let you in. And the airline will not refund you.