I've started with 500$. It was amount, which i was ready to lose. I strongly reccomend to use this one main rule. Tradind with such amount which you are ready to lose. Have good profit, guys!
Once you are in trading better to be ready of what possible to happen to your money and lose is always part of it. But the good and better in trading than the other is because once you can invest a lot of money you can earn a lot of money too as well.