If you have some spare time in your days, you can try to run some of these business ideas. In addition to give you more income, you may get some experience at running a business. It will be very useful for you someday.
If you include a person who has much spare time without any specific activities you can do daily, starting a simple business is a very good idea. Do not be confused about what kind of business you can run, these are some examples you might try: