Stop loss is very important! I actually have no idea how traders can trade without it lol. Trading without stop loss is like a guaranteed way to throw your account! Although admittedly, it's a bit challenging to know the optimal stop loss placement because you don't want your stop loss to close our your trades unnecessarily, of course.
It's pretty difficult to underestimate the necessity of using stop loss. The vast majority of traders don't use it because they think that it restricts their potential income, however it's very important to reduce risks. If you lose the position, it's okay, it's trading and nobody is protected from it. So, always use the stop loss, as for take profit, then here you have to decide by yourself.
A stop loss limits a trader from suffering undesirable loss, everytime market moves against him. An additional benefit of using a stop loss is that it frees a trader from any emotional influence. Market can take a quick turn before you could make any decision about whether you want to hold the position or sell.
Stop loss is one of the most important tools in trading, not only because it allows us to exit objectively from losing trades, but it also allows us to maintain an adequate money management and maintain optimal risk management.