The plugin is translated into multiple languages. So you can benefit from it even without additional translation efforts.
All default plugin content like labels, buttons, system messages will be displayed in the main site language which you set in General → Settings → Site Language.
If you want to customize anything, simply follow the guide right inside Accommodation → Language. You can translate plugin texts using any free program like Poedit, Loco, Pootle etc.
If you run a multilingual website, all your added content should be also translated.