Changing language on Apple website
I am going to be in Japan for a year, and I am looking to order a MacBook from the website. Am I able to change the language to English while keeping the country as Japan?
It's not clear what you are talking about exactly: Changing the language that you see on some website? Or changing the language of the menus and dialogues of a Mac you are buying?
The latter takes a few seconds via a change in preferences and restart.
https://support.apple.com/guide/mac-help/change-the-language-your-mac-uses-mh26684/10.14/mac/10.14