Add custom pages to display legal information
You can create webpages in your Shopify admin. Webpages are useful for publishing information that rarely changes or that customers reference often, like an "About Us" page or a "Contact us" page.
Learn how to add pages to your online store
Add or generate store policies
You can follow up Shopify official tutorial on how to generate store policies content then copy and use it in your store pages you created.
Add or generate store policies