Can you provide a link to the site? It can vary depending on your theme but the QUICKEST method would be finding the author class and putting a display:none; on it via your child theme or custom CSS. I could provide the actual CSS you will need to do so if you can provide a link.
The BEST method would be to remove it via your functions.php but I can’t tell you how to do that without knowing what theme you are using.
You could try adding the following to your child theme style.css or wherever you add your custom CSS.
.date, .polaroiddate {
display:none;
}
They will still be visible for screen readers and search engines but won’t show up on your site.
