question- what are the things that a trader should never do?

Don’t do live trading until you fully understand what you are doing, practice practice and practice on demo first
Traders should never-
1.Trade without using stop loss
2. Invest money that he cannot afford to lose
3. Invest money before investing time
Over leveraging and trading against the odds will also ruin the traders journey of success.
Over leveraging is one of the big trading mistakes, if you have just started trading higher leverages will not work well.. Instead start with low leverages and gradually build your trading skills and benefit from high leverages.
Never trade without a stop loss. You should always have good risk management and only risk between 1-3% of your account in any trade. It takes discipline but once you get used to it you will do well.
Don’t do live trading until you fully understand what you are doing, practice practice and practice on demo first
Yeah, you're quite right. I guess practicing is the best thing ever a trader can do. It helps to understand the main laws of this activity and on initial stages practicing on demo can prevent lots of serious mistakes which on a real account can cause a deposit dumping.
To my mind, the best way to get ready for real trading is to learn a lot and to practice a lot in a day. I believe that learning&practicing on demo are the keys to success in trading. And what is more important is that novices can understand whether thirs activity suits them or not. Often traders bust their accounts and then make a bad conclusions about trading.
In my opinion what trader must do is that do not neglect basic rules of trading, even fundamental rules such as psychology, patience, learning, practicing and once practicing. For me these are the main rules which have to be complied by all traders whether you're a novice or a professional trader.
All you have to do is just to comply with these rules and try not to violate them, afterwards you will see how do the doors into the world of success open in front of you. Practiing and pscyhology matters more for me personally, because psychology helps you to set up your mood on a right way while practicing helps you in everything, starting from the learning ending with mastering of this activity.
Don't start trading on Monday before checking the economic callendar for the entire week - getting surprised by high volatility caused by a big economic event you had no idea about can be very unpleasant.
Yeah you're absolutely right. It's so significant for every trader to check economic calendar mainly because his income directly depends on news which was released at weekends. However, it also depends on what type of trading does a trader prefer, you know. If we speak bout short-time trading then there is no need to check economic calendar because it would be better to use technical analysis for such type of trading. Even when there is a high volatility, there is a chance to make money. Well, if we speak about medium/long time trading then of course news matters a lot in this case. Just keep these schemes.
In my honest opinion trader should never rely on luck. Luck is the last thing a true trader has to draw upon. There share of luck in trading activity is about 5-10 percents (accroding to general experience of many traders). So, if you want to make money in long-term perspective, forget about it. Moreover, I guess that it's very important to know that before novice starts trading he/she has to thoroughly learn not only trading sutff but also brokers, its offers and stuff like that. There are too many scammers nowadays thus you have to dig all the information which you are interested in about broker's platform (withdrawals, deposits, comissions).