Greetings, NekohaShizuku.
It appears that you're receiving emails from Apple in Chinese when you haven't changed anything and you don't read Chinese. Good job on checking the language your iPhone is on, and we're glad to help with this.
Manage and use your Apple ID - Apple Support -- Using a browser on your computer, sign in to your Apple ID account page. Check which language under Account. If it's showing Chinese, change it to your preferred language.
Get Support -- If it's showing the correct language, or you're unable to change it, please contact Apple Support.
Take care.