Trading won't different between rich and poor, both will lose the money if they don't have proper knowledge. Fandmental analysis is easy one but most of people do mistake in technical analysis. So a trader need to practice more about trading and that's why the demo account is perfect for them. And when it's about rich and poor then it's true that rich people have large capital and that's why they unlock many facilities for their fund to manage trading and change their luck and poor people with few capital can't do well in trade even they take high leverage is for trading
Of course everyone can trade whether they are rich or poor. There is no difference between whether they are rich or poor and what differentiates someone in trading is whether they can analyze the market well or not, if they cannot analyze the market well then it will be very difficult for them to earn money. profit from the trading they do and they will even experience losses if they make mistakes in trading.
Yes, it would be better for a trader to always practice and continue to learn about trading so that when trading they can make profitable decisions for the trades they make.