When You want to remove copyrights note from the prestashop 1.7.x classic template, you have to open file
/themes/classic/templates/_partials/footer.tpl
then removie lines 47-51
{block name='copyright_link'}
<a class="_blank" href="http://www.prestashop.com" target="_blank">
{l s='%copyright% %year% - Ecommerce software by %prestashop%' sprintf=['%prestashop%' => 'PrestaShop™', '%year%' => 'Y'|date, '%copyright%' => '©'] d='Shop.Theme.Global'}
</a>
{/block}
Empty block should look like this:
<div class="row">
<div class="col-md-12">
<p class="text-sm-center">
</p>
</div>
</div>
You can removie it too or leave it to place other informations.
Dont forgat to change Performance-> template compilation -> Recompile templates if the files have been updated to update changes in the template.