I first started using bitmex, this is because you can start using around 1,000 satoshi because it has a 100x leverage, I would recommend starting with at least 10k satoshi and buy one contract just to practice.
if you bitcoin trading in bimex use margin trading with leverage 100
is not diference with forex trading, becase same can margin call, youre realy trading in bitmex only use 1000 satoshi
i think only under one minute youre account can margin call