For me, I start by watching some videos and gaining some knowledge about trading. After that, I join some groups to ask some people about the things that I can't understand. The money that I invest in trading/ bought is about 20$ at the moment. The first day I trade is by following some signals to some ppl/groups, and I gain about 2$, and I'm so happy on that time because my first and day attempt is profitable, but the sooner I lose the money but teach me a various lessons and experience that keep and build me a better trader. 
I feel you I try that also ill invest into a $100 but its not big amount ill earn on my first trade in a market its only $15. But sooner all my money gone cause of this buying some coins that I didn't know on what it is until the price of it still down. So lesson learn of that happen, Maybe all of us in here experience on what we experience on the time we trade that we don't have any idea in trading. But now I'm almost careful and read some new advice from the people in this forum.