Help pls

Ok so I am writing a book with a variety of different languages, some of them are going to be made up and others are going to be actual languages.
I was wondering if I should change the name of the real language… Like, turn the word "English" into something else. Would that work or would that make people confused?

If you're not planning on making an English relex (https://en.wikipedia.org/wiki/Relexification), I'd suggest changing the name of all of the languages.

I would change the names of the real languages just because when you read a fantasy book it entertains more if it is suspenseful, and for some languages help build suspense. Hope my answer helped. :)