Some of the most common reasons for Canada visa rejection are as follows:
Proof of Finances: You must demonstrate that you have the funds to fund your trip and stay in Canada.
Source of Funds: The Canadian government investigates how you obtained the funds in your account. Non-consistent bank account deposits might indicate a problem.
Travel History: If you have never been outside of your own country, your application will most certainly be viewed as weaker than those who have.
Lack of work prospects in your home country: If you come from a place where salaries are much lower than in Canada, the IRCC is likely to have reservations about your ability to return after your stay or studies.
Failure to provide sufficient and correct supporting documentation