Study in Canada as a tourist is possible. Change from tourist or visitor visa to study permit inside Canada only take a month to process.
Before immigrating to Canada, people should have a specific plan to prepare for a new life in Canada.
Temporary residents are allowed to stay and work in Canada while their application for becoming PR is processing.
If you are going to apply for a PGWP, you should read this article to understand more about the program and how you can apply for this.