-snip-
No, trading is not a bicycle, and it is impossible to learn how to trade without theory, as this will lead to the loss of a deposit. And with regard to your example, it may happen that someone who has ridden a bicycle for the first time may have an accident, the consequences of which may be disability or even loss of life.
Some people are too quick to conclude that trading is bad after one or two losses - but it is true that trading can be a bad choice if a trader does not know how to do it. The trader's consistency with his plan and strategy is very important in this case - I mean, they should not change their strategy even if they suffer losses during the experiment. The market can sometimes be unpredictable and it can make them lose money - but there is always a way to not lose everything if they have the skills.
TP and SL are two mandatory things that every trader must determine the value of. If they set TP limit at 2% - then they need to set SL at 1%. They should be consistent like that and keep trading - but I strongly suggest them to have a trading record for at least 30 days. The first day can be a loss - but the second is a profit, they should record everything for 30 days and calculate the performance after that.