Foreign exchange is good, but the firm offer is difficult to make money, and the deposit is more troublesome. Brokers are all foreign, and there are too many junk companies, which is difficult for novices to distinguish. If you want to enter the business, I suggest you find a good person to teach you or pay attention to it for a few months.
Gold is also very good, but the threshold is a bit high, and most gold trading companies in China are very bad. They always make money by betting, and the good market falls, deliberately affecting your judgment.
I have done all these industries, and finally chose the deposit. Choosing a good brokerage as a deposit should be the best investment channel.