At this time, WCAG doesn’t require specific font sizes for conformance. For main body text, 16px is a popular (though unofficial) base font size. It’s common for secondary information like copyright details to be slightly smaller, such as 14px.
Conformance with WCAG does require that all text can be enlarged up to 200% without loss of content or functionality. This rule applies to all text on the page, including the copyright information. By following this criteria, you will help ensure that users can adjust the font sizing to meet their needs.
To learn more about designing with accessibility in mind, explore the Accessibility Concepts for Marketing and Content Creators course from the Accessible Web Academy.