This will depend on whether your student visa allows you to work. In some countries, there are restrictions on the number of hours of paid work you can undertake during your studies. During term time, there is often a maximum of 20 hours of paid work per week, with full-time work permit during holidays. You can also check these requirements from selected university and their official government sites. If you work while studying, it’s not a good idea to rely on your earnings to cover living expenses, and in many situations, you’ll need to show that you have enough money to support yourself when you apply for your visa.