Hi Jed
There shouldn’t be a blank space to the right of the products. I suspect that you may be seeing an empty sidebar. Have you set the page to be ‘no sidebar’ in the page editor?
There are a couple of ways of changing the number of product columns in the free version, depending on your setup. The pro version also allows you to change the number of products per row.
What is the URL of your site please?
Are you using the WooCommerce shortcode to display products on your homepage or have you set your homepage as the WooCommerce ‘Shop Page’?