It is possible to translate the customer facing interface in the language of your choice. It is also possible to allow customer to select the language while doing an order lookup. Pls take note that a customer can only select a language which has already been added by the administrator in the backend.
Creating New Language.
In order to add a new language go to Settings > Languages Settings
It is possible to create multiple translations. Simply add a new language and start translating it. Refer to the screenshot here
Take note that only one language can be activated at a time. So you can have multiple languages like Hindi, English, Chinese etc but only one of them can be activated at a time.
Let customer select the Interface Language
It is also possible to allow a customer to select the language at the time of order lookup. This setting can be activated via the Language Selection . Click here to see how the language dropdown setting works for customer