Now that ZOOlingual is installed a new section under the namespace zoolingual will be available in the configuration of every element.
For elements with language specific content, like text or textarea, create as many copies as languages are in your site and specify to each one a language. Make sure to assign all of them to the same positions and customize the rendering if required.
For elements which values are universal, like numbers or dates, keep only one element and no languages assigned. On the layouts positions, though, assign the same element multiple times, one for each language, set the language and customize the rendering.
Repeat the process for each App and Type where translations are required.
If the language settings are missing, make sure the ZOOlingual Plugin is enabled.
For further information on setting a multi-lingual site with Joomla! check the official tutorial.