add few certification logos at the bottom of our home page
depending on how far at the bottom, this is probably done with editing footer.php of yur theme, and adding some conditional code;
<?php if( is_home() || is_front_page() ) : ?>
html logo coding
<?php endif; ?>
where exactly, depends on your existing theme;
the best would be if you post a link to your site to illustrate what you have now; you can then also point out in more detail where you want to add the logos.