Determining what path you would like to take in your trading adventures is very difficult to start. I suggest you to check out Whale Club it's a nice place wherein you could ask more questions and learn technique use by other bitcoin traders. If you trade only the top 3 or so coins (that is Bitcoin, Ethereum, and Litecoin), or GBTC, then the chances of losing everything overnight are slim (not impossible, but slim). Other cryptocurrencies are more risky.