Hi Nathan!
You can find all the image sizes that are being added by us/the theme in the functions.php file
add_theme_support( 'automatic-feed-links' );
add_theme_support( 'post-thumbnails' );
add_theme_support( 'woocommerce' );
set_post_thumbnail_size( 220, 150, true);
add_image_size( 'widget-image', 94, 70, true);
add_image_size( 'thumb-image', 600, 450, true);
add_image_size( 'thumb-image-twocol', 900, 675, true);
add_image_size( 'thumb-image-onecol', 1280, 960, true);
add_image_size( 'blog-image', 1280, 9999);
add_image_size( 'full-width-image', 1280, true);
add_image_size( 'full-width-image-gallery', 1280, 720, true);
All other files are most probably generated by wooCommerce.
Cheers