Display Language
Visual Studio Code ships by default with English as the display language and other languages rely on Language Pack extensions available from the Marketplace.
VS Code detects the operating system's UI language and prompts you to install the appropriate Language Pack, if available on the Marketplace. Below is an example recommending a Simplified Chinese Language Pack:

After installing the Language Pack extension and following the prompt to restart, VS Code uses the Language Pack matching your operating system's UI language.