By "generating money", I assume you mean specifically producing an income stream. With a little over $3k to invest, providing meaningful capital to a startup may not be realistic.
Cryptocurrency daytrading might produce an income stream - or you may lose your shirt, and you'll be playing against people who do it all day. The short-term equity game is basically zero-sum. This applies to day trading equity stocks, currency, metals, commodities, etc. as well. Holding equity long-term in a diversified portfolio builds wealth but does not produce income (now).
Reselling and/or retail arbitrage might make you some money, but you might find that it's hard to get enough quantity and margin to produce long-term income proportional to principal (you might turn $50 into $200 this way, but probably not $5000 into $20000).
Stocks are quite viable at your income level, however. Specifically, stocks - or mutual or index funds - which pay regular dividends can give you the potential for capital appreciation and an income stream. These are riskier than bonds and annuities but typically will pay off over the long haul. Some stocks pay dividends around 5%+; so your $3k investment could start turning as much as $150 per year, right now - not counting capital appreciation for possibly another $150 per year. Not too shabby!
Next come the bonds. You can buy federal treasury bonds for around 2.5%+ now. These have very low risk, but do not offer capital appreciation. Most likely, you can do significantly better with tax-free municipal bonds, possibly 4.5%+. If you live in a place where municipal bonds are not taxable at the state level, you can also save significantly on taxes; the "real" interest rate accounting for this could be closer to 5.5%+. $3k is a little low to get etarted but you can probably find something in that range.
Nect come annuities. You can buy an immediate annuity today for $3k and you'll get paid some amount every month for the rest of your life, or until the financial system basically collapses. Sounds great, right? Expect $120/yr or possibly less (and you don't get the principal back at the end). You might be able to get an annuity for $3k, or there might be a $10k (or higher?) minimum.