I recently tried putting a few dollars on Kraken just to see how everything worked, and honestly the fees eat you up pretty hard with such small amounts, but if you see it as paying for a class to understand how this all moves, then it's worth it. What I'd do is just start with Bitcoin or Ethereum, they're the least volatile cryptos (and that's relative, you know), and sleep easy knowing that those 50 dollars is money you can afford to lose without it ruining you.
The important thing is that you verify the platform where you open your account has two-factor authentication and that you don't put in more than you're willing to see disappear, because the crypto market is pretty unpredictable and anything can happen. If after a while you figure out you're actually interested, then you scale up with more money and you already know how the system works.