Adding my own custom template page but got white page

I think it would be best to do a template override in Woocommerce.

If by single you mean a page when viewing only one product then look at the single-product.php template.

The directory it needs to located is: /public_html/wp-content/themes/your-theme/woocommerce/single-product.php.

You can download the template overrides from woothemes.

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