When I'm also new in bitmex, I deposited small amount of money for the testing stage only. I practiced for that capital until I have learned the movements of indicators, the chart and the volume, etc. Then when I have decided to take it to the next level, I have deposited enough capital the amount that I can still managed even if I lose.
Leverage trading is not the usual trading yoh are thinking, OP. So, I suggest you do the practice in bitmex testnet first. Then, deposit maybe around $50-$100 first then you may add up higher amount if you gained confidence and knowledge.
If one has big amount to trade with already, I dont see why one should go into leverage already, we can take a less risky trade and make money without having to leverage. Now that bitcoin has a bull run market, which is usually the best time to trade, I think anyone can make it big.
Within the past few months since bitcoin has started increasing, I have make at least 5x of my investment which was traded in a safe way, I know that one could use leverage to trade between 2x to 100x, but the risk is what I cannot imagine, but fir any trader who thinks that he knows the in and out of trade and will never fail, then there is actually nothing bad in trading with 10x, if the person is lucky to catch all the highs with 10x, then he is made already.