$50 is a very low money to start in investing. I prefer to you to join in some signature campaign and you can earn a small amount of bitcoin or just go in the trading but in trading there is a high risk.
Sorry, but I beg to differ, I don't think there is any low amount in trading. One can even make 100X profits even with the amount like $1, $5 or $10. It's less about how much money the investor has and more about how he use his skills. I have seen that some people have ruined their thousands of dollars in scam coins and on the other hand some people made multifold profits on their investments.