Magento2 Facebook Wall Post module installation is very easy, please follow the steps for installation-
or
Specify the version of the module you need, and go.
composer require webkul/magento2_facebook_wall_post
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy
now module is properly installed
For Magento2 FacebookWallPost module's working process follow user guide - http://webkul.com/blog/facebook-wall-post-magento2 also check other magento 2 modules https://store.webkul.com/Magento-2.html