I am not that expert in trading but i would like to suggest for you, better start with an amount you can afford to lose, just like gambling while you are practicing you can start by trial and error, because mostly you wont learn unless you try it for yourself, so better try for smaller amount because when you failed then it's not that hard for you to start again.
Yes just for learning you can start from $10 to how much you can afford. But to make a profit in short time, you should invest some more money. Yes with just $10 you will not be able to make a good profit. Here you will not learn any new thing. To learn the new thing you must try to invest in popular coin. To buy the popular coin, your investment should be a little bit high. Min $50 is good to start your trading.