How do I remove the word “Blog” from a WordPress Homepage?

The file where you could delete the text is index.php

This is the line containing the text, so you could remove this line.
<h2 class="section-title"><?php echo esc_html__( 'Blog', 'catch-vogue' ); ?></h2>

For future reference, if you were to update the theme at a later date when an update becomes available from the theme author, the file will be overwritten and you would lose the change you made. To avoid this you can look at creating a child theme to make your changes, so that you can update the theme in the future without losing any modifications you may have made.

https://developer.wordpress.org/themes/advanced-topics/child-themes/