There's plenty of volatility in FX, but it's tradeable volatility. Bitcoin has blow out your account in one trade volitility; that's why it blows my mind that people feel like it's a good place to learn. It's not a true trading market; that amount of volitility makes it a casino. It's probably the worst place you could possibly learn.
Coming from a position having of closed my account with Interactive Brokers (who are great, if you're looking for a proper trading account) back in March... Bitcoin is a HELL of a lot easier to learn on. Sure, the volatility is insane, but you're not trading against people with unspeakably more resources than you, or risking nearly as much. Minimum trade was $25k, and typically you wanted to be trading $100k at a time to keep commission low. That's all done on margin, of course, so you're actually trading 50 times as much money as you have as a deposit.
Yes, you can get Forex mini accounts, they're all with market makers where the price you trade is determined by the person holding your money. Even with the few really reputable companies, that's just not a good situation to be in.