Is this Plagiarism? (I'm pretty worried)

So, basically… would it be necessary to cite Shakespeare’s Macbeth quote ‘What’s done is done’?

No… @LizzieElizabeth I meant on its own, perhaps describing the circumstances of a story. Or… if I use the quote ‘To thine own self be true’, Shakespeare, as describing a fictional character, would I need to cite it?

@LizzieElizabeth Thanks so much! You’ve really helped me!

@LizzieElizabeth All the same, can you please give me an example in which a Shakespeare quote will need to be cited?

If you find a fact on wikipedia that you want to use, google (or google scholar/database search) that same fact and find a reputable source to cite. This also gives another source to research from.

Ok… so I’ve been submitting essays to a few local contests, and to make sure that most of my work is unique, I’ve been using Plagiarism checkers.
However, I have a question- when you type or upload something into a checker, does your work become property of that checker, or can they keep track of it- or does it simply scan your work and let you know?

I’m quite concerned about this, and I really want some responses.

Another q-

Do I have to cite the assertion that Hinduism is a dominant religion in India?

Yes.

You don’t need to cite the Hinduism thing; it is well known that the majority of India’s population is Hindu, just as the majority of the population of Pakistan is Muslim.

Wikipedia has a list of well ordered citations. Is it all right to just use those when taking something from wikipedia?

You still have to see if those sources are credible; they may not be.

So… I have another question…

In a paper, I’d like to include John Green’s famous lines- “[I’m] on a roller coaster that only goes up” within a sentence, since I’m describing technological improvements. I’m using the line more to strengthen my claim rather than to bring attention to the actual phrase. So do I need to add a note saying that this is John Green’s quote? If yes, how?

In the words of John Green, “X.”

Alternatively,
In the words of Augustus Waters in John Green’s The Fault in Our Stars, “X.”

But if you’re describing technical improvements, there HAS to be a better and more professional way to say that than a quote taken from a cancer love story.