[Jugglerofworlds]

I went down this path about a month ago. Don't expect to find any good quality data on stocks for free. If you do need data on stocks I recommend IEX, but expect to pay a good amount of money for any sizable amount of data. I paid around $100 to scrape the historical daily data for the Russell 2000. Getting intraday data for any sizable time period would cost an astronomical amount of money due to the way IEX charges for their data.

For forex, the situation is a bit better - you can get information from Dukascopy/Tickstory for free. For cryptocurrency there is data available from Binance.

There is also QuantConnect, which is an online IDE/system for developing manually coded trade bots. They have historical data for a wide range of financial products and it's all available for free. The catch is that the data can't leave their system, which eliminates the possibility of training any sort of advanced machine learning model.

Edit: for these types of questions I would recommend searching /r/algotrading