Hello,
1/ You can create static blocks with the desired content, then go to Edit products > [8theme] Product Options > select block for Additional custom block option. Then go to Single Product Builder and add the Additional custom block element into page content.
2/ Texts/static blocks can be added to the content of Single Product Builder via HTML elements.
3/ If this is not what you are looking for, contact support of WooCommerce plugin and ask for advice.
Regards