There are many online paid and unpaid sources to learn about stock markets from basic to advanced technical levels. However, whatever source you choose you can not find everything about the stock market under one roof.

If you are looking for a basic understanding than Youtube also can be an option for you. For little technical chapters of the stock market, you can further subscribe and watch the paid videos through various YouTube channels by market professionals.

Last but not least, you can anyway check InvestorQ platform for free learning of topics like eg. how to analyse the stock market in different conditions and work accordingly; more 18 such topics related to markets: https://investorq.com/faq.html