The amount of profit one can make from trading will depend on two things: how good they are as a trader, and how much capital they have.
Capital is really a big factor in trading. If you have a small capital, the profit you will earn might not be worth it compared to the stress you will undergo in executing successful trades.
Knowing how to trade doesn't mean you can have a better life. In fact, it's even more stressful than having a full-time job. Your emotion is your biggest enemy in trading. Aside from being financially capable, you should also be mentally prepared to control your emotion when the market is unpredictable and you experience consecutive losing trades.