Easy way is to use the custom CSS –
.entry-header {
display: none;
}
.blog #content .post.hentry, .archive #content .post.hentry, .search #content .hentry, .single-post #content .post.hentry {
padding-top: 20px;
}
If you need the same to removed completely from the HTML generated instead of hiding using CSS, you can override the templates in your child theme. You just need to copy templates files templates/archive/content-post.php, singular/content-post.php file to your child theme and then delete the line –
<div class="entry-header">
<?php get_template_part('templates/meta/published', 'custom'); ?>
</div>