Of course you can do this. You just have to buy btc or ether with your small amount and start trading with them in an exchange. But bear in mind that some coins can`t be bought under 10$
small amount is enough for you to start that was i really and highly recommend also when someone ask me that question cause you have to trade the amount that you are wanted to loose for you afford to loose for cause it is hard with your feelings if you might start in a big amount then you are not able to loose it.