To avoid entering into negative side of bitcoin as you said, what you need to do before you invest on bitcoin and before you venture into trading of bitcoin or any other cryptocurrencies is that...at first you have to know that blockchain technology is broad and without paying attention you will not understand the clips of it...for the aspect of bitcoin you have to know that you're supposed to make a proper investigation about or research of bitcoin, to know if you will venture into the long-term investment or short-term investment, this things are necessary for cryptocurrencies investment especially Bitcoin and also when you are a beginner

Secondly you can learn from YouTube videos, were tutorials of bitcoin investment and also read different text books of bitcoin, that will make you to comprehend more better....for the aspect of trading, a trading very crucial something that is very skillful, in which you need to learn the basics manually and advance it with online studies, and you need to know the method of it's application, so that you wont end of losing your capital for first time of trading...

Please, read up from the links presented to you or suggested by the forum users, such links will enable you to know things you don't know about cryptocurrencies.