Common mistakes of those newbies in trading are being hyped and excited about the profit they are seeing when they see advertising or influencers that are flexing their earnings from trading. They think it is easy as that without knowing that those influencers or ads don't show the hardship or grey part of trading.
I believe a lot of people go into trading due to these advertising and flexing, you can't really tell why people choose to do some certain things but I'm confused people trade due to these flexing and hype. Sometimes when I hear people stories on how they started trading or I watch motivational videos online concerning their early stage, they'll always indicate it was not easy and of course you must lose to win, this is the common principle of trading and newbies should get used to loss for them to last longer in the game.
Some newbies seems to be very smart and I've seen most of them condemning signals, it's best to learn rather than relying on someone else.