After having WordPress installed, you need to install WooCommerce plugin.
Watch the below video or follow below links to learn how to install and use WooCommerce.

 

WooCommerce 101 Video Series – a step-by-step guide onsetting up your own WooCommerce store, created by WooThemes.

 

• WooCommerce plugin documentation: detailed guideline on how to use WooCommerce
• WooCommerce Blog: updated information about WooCommerce
• WooCommerce Help Desk: submit support ticket for problems related to the WooCommerce plugin