If you are not a permanent resident of Canada or a Canadian citizen, you need a work permit to work in Canada. Tourists are not authorized to work in Canada.
In most cases, you will need a job offer from a Canadian employer before applying for a work permit. There are also so-called open work permits, where a prior offer is not required. Examples of people with the possibility of obtaining an open work permit are students who completed their programs at a designated institutions, the companions of people who have work or study permits, refugee claimants, among others.
You can review the different categories of work permits o this website, and of course, if you have questions, contact us.