its not like whenever you buy an asset it's bound to go up in value!
if trading was that simple everyone would just be buying things, selling them at a higher price & be done with it!
it requires knowledge, skill, experience & an understanding of the underlying events forming the value of the market you're trying to involve yourself in!

for a start drop by investopedia.com, the site has an entire section dedicated to trading;
there are numerous amazing, informative & free articles there about the mechanics, fundamentals of trading & everything else markets;
(the articles are not directly related to cryptocurrencies but the principal is universal!)