Hello @isabella92,
Like just uploading the pdfs etc. in the media library, then linking to them in /downloads? Or is there no easy way to customize what that “page” looks like?
Just to confirm we’re on the same page: you’re looking to add specific content visible to all customers in the downloads tab within the ‘My Account’ page, correct?

Link to image: https://d.pr/i/DHIuDX
You can find several WooCommerce action hooks for this section of the my-account page illustrated in the following guide: WooCommerce Visual Hook Guide for Account Pages
Let’s take the first hook as an example to add some dummy text that redirects to a manual PDF.
add_action( 'woocommerce_before_available_downloads', 'display_pdf_link' );
function display_pdf_link() {
// Replace 'your-pdf-file.pdf' with the actual file name and path
$pdf_url = 'https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf';
echo '<p>You can find our guide by clicking <a href="' . esc_url( $pdf_url ) . '" target="_blank">this link</a>.</p>';
}

Link to image: https://d.pr/i/v0ANSC
To learn more about WooCommerce actions and filters, please check https://woo.com/document/introduction-to-hooks-actions-and-filters/
If you require the assistance of a developer, consider hiring a WooExpert as we’re not able to provide support for custom solutions per our support policy.
Let us know if you have any other questions.