WordPress: Add WooCommerce Support In A Theme
To add WooCommerce support in a WordPress theme, you just need to add this line of code in the functions.php file and then install WooCommerce plugin. This will add all kinds of WooCommerce functionality to the theme.
WordPress: Enable Featured Image In A Theme
Most themes already come with this support but if you are building one from scratch and you want to add this ability, just add this add_theme_support code to the functions.php file.