What is WooCommerce?
WooCommerce is a WordPress plugin. FooEvents is an extension plugin that adds additional event and ticketing functionality to WooCommerce.
Why do I need to install WooCommerce?
FooEvents extends the ecommerce functionality provided by WooCommerce and adds ticketing and event capabilities. Before installing FooEvents you must FIRST install WooCommerce
WooCommerce Installation Instructions
If you are new to WooCommerce it is recommended that you go through the WooCommerce documentation: http://docs.woothemes.com/documentation/plugins/woocommerce/getting-started/