Common mistakes and problems of traders are not having experience and immediately attempting to trade, others are being control of their emotions instead of thinking about it before deciding and trusting easily.
I agree,some are incourage to engage in trading without proper knowledge on how to trade because they heared that somebody got rich because of trading.Other factor is being impulsive because you don't know how to control youe emotion like for example, you heared some negative fake news then you easily jump into conclusion on withdrawing your investment because you are afraid you might loose your money without reviewing first whether that news is true or not.
this is some mistakes also that you may not yet even know , and you may finally knew how important is basic knowledge and research while you are in trading and you may have a lot of mistakes , well even that you have a lot of knowledge but you may not take some experience you may never understand what you are doing too. take all in a balance situation