Hi,
For the language file, we always recommend to use the override section (the second text zone) in order to keep your overrides with updates.
For the views, we always recommend to use the view override (display > Views) in order to keep your overrides with updates.
For your views, you just have to open the view of the files that you have modified directly and save them. (open them for the right "front-end" template).
It will create the override file and you will be able to update without problem.
For the language, it will be more complicated. I think the best is to copy in a local file the content and restore it after the update. But the best is really to uses directly the override section.
With this copy/paste trick, you will loose new translations that we included (at the end of the file).
In all cases, I recommend you to make a backup of your website before the update. In case of you forgot a file.
Regards,