The code you posted at https://codepen.io/anon/pen/NXJXXE is fairly complex for beginner learning. It is 3 languages at once. I would concentrate on HTML first (do you know  ?), then CSS, and finally Javascript.
Maybe you should start with something simpler.
Beginners should not skip along until you understand everything, and can reproduce it several different ways.
Hate to say it, but your JS style is kind of atrocious. Try refactoring your code to eliminate one of the functions. Try replacing throw-away vars with functions or inlines.