I honestly think that you should stay away till you understand what Bitmex actually is.
It's not a regular exchange, but a platform where you can buy yourself into various types of contracts speculating on the price of Bitcoin or other altcoins to either go up or down. Depending on how much leverage you go with or the contract type you buy into, there is a chance that you will lose your entire position.
There are plenty of newbies depositing Bitcoin to lose it all not long after, and from there blame the exchange for being a scam, or that they have been hacked and someone stole their coins. It's not something to underestimate.
Read;
https://www.bitmex.com/app/faq