Trading safely is key but without any losses is a myht only if you choose to buy then ignore that is the only way to trade without loss. Safety is key and it's basic from the exchange site you choose to trade, to the type of coins you want to trade, down to how you withdraw but the greatest security anyone can engage in is to ensure not to put all of your resources on an online exchange the moment you have done that , you have compromised on any level of security.
I suppose you meant to say myth!
At any rate, it's near impossible to trade without any loss and must say it's inexperienced traders that like to indulge in such day dream. For real, you're already fighting with a loss starting from the deposit fee, spread and then the withdrawal fee at the tail end and that is, for the ones that get there. All said, what knowledge and experience bring the way of a trader is the ability to win more than they get to lose, that makes your knowledge in the field, the security you need.