I think every trader should pick the most suitable one. The only thing I can recommend is discipline. Good thing is that there are plenty of assets available at FXCC, so I am sure you will find some for comfortable trading.

I would suggest you to try out crypto, oil and some of the volatile forex pairs like RUB, TRY, ZAR or PLN pairs. Those are the ones you will probably catch the biggest moves. So, if you get the direction right, you might make bigger amounts of money utilizing less leverage.

The minimum amount for withdrawing money from FXCC is 50 USD. I don't think this is a large amount.
I think you should try popular currency pairs like EUR USD or Bitcoin.