I reckon you only have to be 18 to get a CFD account in Australia, when you're considered an adult here in Aus.
CFDs are pretty risky though. You can lose a lot, and also lose more than you have on a CFD short. It's totally up to you but I'd make sure I have a consistent win rate before I attempted CFDs. You can get some pretty good gains on penny stocks without having to use leverage.
Some other forms of leverage are; - Using equity\margin lending from your broker. For example, my broker is Nabtrade and you can get a margin lending account with them where you can borrow funds to invest in about 581 different Aussie stocks. The penny stocks are never on the approved list though. - You can get a dedicated personal loan for shares, but it has to be strictly only for shares if you want to claim deductions on your tax.
I would caution against using leverage though. Warren Buffet once said, "If you don't have leverage, you don't get in trouble. That's the only way a smart person can go broke, basically. And I've always said, 'If you're smart, you don't need it; and if you're dumb, you shouldn't be using it.'"
