Become a user tester. There are sites that will pay you $10 to visit a website for 10-20min and record your experiences as you browse around. This helps the site owners know what it’s like for a stranger to use their site so they can identify rough spots and make improvements.
Sell things you, your family, and friends no longer need on eBay. (Reselling stuff on Amazon can also be lucrative, but it’s a bit more advanced so I’d only recommend this if you have someone to teach you.)
Identify an open market and create a book, t-shirt, or e-course to sell them. You can create a professional book, t-shirt, or e-course without spending a dime or stocking up on inventory. (Email me if you need help with this.) The important thing is to have people to sell to before you create the product. Think: what’s something a lot of the people you know would want to learn about/support/buy? Create a product to fill that niche. Alternatively, if you know any bloggers, public speakers, or other authority figures with an audience, is there any product their audience might like that you could sell to their audience through them?