How long you are allowed into Canada is entirely up to the CBSA officer you encounter at the border. Typically visitors are allowed in for the default six months. However it's quite possible to only be allowed in for a shorter period of time if the CBSA officer has concerns about your intentions (i.e. believes you plan to remain in Canada long term) or if you have insufficient ties to your home country. To try to make the process as smooth as possible for yourself, ensure you pack like a tourist (i.e. only bring a suitcase or two and don't bring things that short term tourists usually don't bring), if you are flying make sure you have a return ticket, ensure you can show you have enough money to support yourself here without working, would be good to carry proof of travel insurance, and if possible, it's always a good idea to carry evidence of ties to your home country (e.g. property, employment, assets).