Full-time international students can work up to 20 hours per week. They can work full-time when the program is on break (usually in the summer).
There is no maximum monetary amount that may be earned, only hours.
The provincial minimum wage varies. In Ontario, for example, it is currently $11.40, but it will be $15 in around 18 months.
The regulations for co-op terms are varied.
I highly advise you not to come to Canada if you cannot afford the entry fees and living expenses. There is no certainty that you will find work as a student. If you do acquire a job, there is no assurance that you will work 20 hours per week. There is no certainty that you will acquire a job as a student, and even if you do, there is no promise that you will work 20 hours per week.
The finest student employment is for graduate students working as teaching or research assistants. However, there is a lot of competition for these positions.