I guess it depends on your skills and interests. You could look at starting an online business or focus on a local business. If you ask people in your location, you might find a particular service that is missing or has a shortage in your area. Some examples are tutoring (second languages, music, software, school subjects), cleaning services (homes, boats, cars, offices), computer support, landscaping, delivery services, repair services, pet services, event planning, and there are many more.