In order to display your website in another language, a new sales policy must be created and assigned to the intended language through the Culture Info field.

With the sales policy already created, you will need to adjust the front-end of the store to enable changing the language and, consequently, the trade policies. To do so, you must define that for each language the URL must include the parameter ?sc=salespolicyid, changing the salespolicyid value for the sales policy Id that was set up and assigned to the desired language.