One of the most important challenge a trader face is facing uncertainity during market hours. Its in our nature to feel that we are in control of things happening in life. So we always want a secure situation in our life. When it comes to trading, the entire envirinment is different. Price movement is not in our control. We can not control the market, but we can control the way we trade. Always plan your trade with proper entry, exit & stop loss. Lack of planning your trades, make you to take impulsive trading, which will give loss and the loss will take away the confidence you have about your trading skills.
Dont trade with big position size if you are a newbie. Dont risk the amount you can not afford to lose. Preparation(trading plans) and risk management will make facing the uncertainiity in trading easy.