Common lines of code don't come to me easily while I'm doing the quizzes or code challenges. Is there an easy reference of these I can use?
The MDN documentation is always a good bet. I typed "document write MDN" into Google and got the fast track to the basic article.
Just as an example. The MDN docs usually do a decent job of giving an example of usage, but you need to scroll down past the definitions and lists of properties and methods sometimes.