Ok, here’s an example of where you can put the snippet.
In your functions.php file, you will already likely find add_theme_support function calls.
In my original functions.php file, I have the following starting after line 20 in the file:
/** Add support for custom background */
add_theme_support( 'custom-background' );
/** Sets Content Width */
$content_width = apply_filters( 'content_width', 680, 680, 1020 );
I added the genesis-connect-woocommerce line after the add_theme_support line. So now my functions.php file has this:
/** Add support for custom background */
add_theme_support( 'custom-background' );
/**Add support for genesis-connect-woocommerce plugin */
add_theme_support( 'genesis-connect-woocommerce' );
/** Sets Content Width */
$content_width = apply_filters( 'content_width', 680, 680, 1020 );
As other users have said, when they say anywhere, it is really anywhere. But if you are totally new to php and have no idea where a statement ends and where another starts, a good idea is to add your line after a blank line in the functions.php file.