If bot comes with a pre-determined strategy, that strategy no longer works and is useless, because too many people use it or know about it.
If bot allows you to implement your own trading strategy, then it is a good and useful bot, but it is on you to figure out how you'll tell him to trade.
Learn it manually first, if you can make consistent small profit, only then start exploring ways to scale it with bots. Before all that, you should trade with fake money and back-test your strategy, and then also forward-test it. Some say start with real money right away to try and get emotions under control, but I advise against it.
Bots that "work" are not meant to be used by beginners and the word works only means that it is easy to implement a strategy that you already know and act on manually. Bots that never worked and are a scam are advertised at beginners specifically. What you are currently seeking, doesn't exist.
