WooCommerce - Number of products per page
There are two ways that you can change the number of products displayed on each page in WooCommerce.
1. Reading Settings
Go to WordPress > Settings > Reading. Under "Blog pages show at most," put your desired number of products. Keep in mind that this controls both your number of products and the number of blog posts per page, so it's going to change both.
Why the number of products uses the same setting as the blog posts... the world may never know. ;)
2. Code Snippet
If you want your number of products per page to be different than your number of blog posts (very understandable!), you can use this code snippet from WooCommerce. Paste the code snippet at WordPress > Appearance > Editor > Functions.php at the very bottom.