The PDF guide and videos may feature slightly different search terms, but the principles are the same and you can use either medium or both to complete your assignment. And, of course, you can email me or use the chat button if you have any questions.
I suggest beginning with an article rather than jumping directly into searching for cases because: the context and explanation of a case will help you determine if the case is relevant for your paper, and if it has any significance beyond itself.
Having said that, no matter where you choose to start, you will eventually search for both cases and articles.
The terms decision, opinion, and case are interchangeable. They all refer to the judges' written explanation of their disposition of the law suit.