If you have a yard or some space to grow food, you could grow items to sell to your friends and neighbors. If you have enough space to grow a lot of food, you could even join a Community Supported Agriculture – where local farmers and residents pool together to buy and sell fresh produce. This may not make you a millionaire, but if you have enough to sell consistently, it could be a great income stream.
Another popular site to earn money doing gigs is Amazon's Mechanical Turk. You get paid a very small amount per gig (sometimes as low as $0.05) but you can do these tasks very quickly. For example, you could be asked to identify a picture or type certain text. When I was in college, I used to do these gigs in class and earn money while taking notes.
If you are fluent in one of these in-demand languages, then you can earn some money on the side by providing translation service when you have free time. You can find translation jobs by joining translation agencies or freelance sites. There are different types of translation jobs to choose from based on your skillset. Here are some websites or companies where you can find translation jobs:
Once you have a little bit of money, you need to start investing it. The goal, of course, is to turn your investments into a passive income stream that will pay you for the rest of your life. It doesn't take much to get started. You can get started investing with as little as $1 with these free investing apps. Then, add another $100 each month and you'll grow your nest egg into something powerful.
Busy professionals outsource their laundry more often than you would think. If you live in a dorm or apartment building, you could offer to start a laundry service for all your friends and neighbors. Instead of them having to make their own trip to the laundromat, you could combine their trip with yours, and charge them a small fee for it. Considering you do laundry each week, this could be a great recurring revenue stream.
Search for freelance writing and editing gigs. The rates for these jobs vary: you may be paid by the word, be offered a flat rate for a project, or in some cases can be paid an hourly rate. You typically won't be able to retain copyright over your work or collect royalties, however. Even so, by doing freelance work you can build a portfolio and make valuable connections which may later pay off with more stable job opportunities.