When working with WC you more than likely need to use one of their action hooks to show the field where you want it shown on the product page. https://docs.woocommerce.com/wc-apidocs/hook-docs.html
In your action you need to get/show the value by passing ACF the product ID (Post ID), example: get_field('your-field-name', $product_id);
Some of the action hooks pass the product ID and in other cases you’ll need to figure out how to get the ID.