Somehow, I figured out how to buy & sell stocks when I was just 21 years old and didn’t have much money. These days it’s a whole lot easier. There are many online stockbrokers and once you have an account you can buy & sell using your computer. I’ve been doing it for many decades. You need to restrict your stock purchases to those ‘greedy’ companies who, in your opinion, are really screwing their customers and are racking in the money. What could go wrong with that strategy?