Infinites outside of math? CORRECTION to the post below. This answers proving that card(R) = card(RxR), which is not what was asked of me. Instead, what was asked of me is "how many times N can be mapped on the real line?" If that is taken in the sense of what is the cardinality of {f | f is a function from N onto R}, then of course the answer is 0.
I'll leave my remarks about card(R) = card(RxR) anyway:
I have been referencing the more general theorem that for an infinite set S and natural number n>0, we have card(S) = card(S^n). S = R is a special case of that. I'm not sure, but it seems perhaps the particular proofs mentioned in threads here lately for R don't use the axiom of choice (?). I have not studied those proofs to verify them for myself though I get the gist of them and they seem okay to me to that extent.
The proof I have studied of "for an infinite set S and natural number n>0, we have card(S) = card(S^n)" is in Enderton's 'Elements Of Set Theory'. It is pretty involved, two pages, requiring a number of previous lemmas, a proof that the axiom of choice implies Zorn's lemma, closure under unions of chains, and more (and even an illustration to aid intuition). I would not spend my time and labor composing it all for you in the confines of a post, and it would do you no good anyway since you are utterly unfamiliar with even the basics of set theory that are prerequisite let alone the mathematics of Zorn's lemma, chains, et. al. And I admit that I am rusty myself on some of the details now, though I have previously studied it in every detail to verify for myself that it is perfectly correct.
The best I can do for you is to recommend that you get a textbook and study it from page 1. Enderton's 'Elements Of Set Theory' in particular is widely used, highly regarded, beautifully written, and pedagogically exemplary. Though, I would actually first recommend at least gaining a basic understanding of symbolic logic.