Bitmex is only offer margin trading and this is will be more risky than spot trading because use of leverage, if you want to try it use low level of leverage and avoid greedy. For beginner trader should be looking for tutorial on the google how to trade there because way to trade is more complicated than on exchange spot trading, because the number of contract that we can buy will be according to also with level of leverage.
He still looks like a beginner trader and from his question you could tell that he is going in for another big loss, sorry to say, someone who is prepared for trading in real life should have at least know much about basic things through theory such as stop loss and other tools used in trading which are basis of trading and not the complicated ones. He still has lots of things to really learn and not just jump into trading, not even demo, theory stage is need here before the practical sets in.