This custom CSS should do the trick:
.site-info {
display: none;
}
Don’t edit the theme files directly, otherwise your changes will be overwritten whenever the theme is updated.
An easy way to add custom CSS is to install the Jetpack plugin and activate the Custom CSS module. You’ll then add your custom CSS in the new stylesheet editor that’ll appear in your dashboard, under Appearance > Edit CSS.
As alternatives, you could either install a standalone custom CSS plugin, or create a child theme.
If you’re using Infinite Scroll, you’ll need another method to remove the special footer that one comes with, but without seeing a link to your site I’m not sure if that’s the case.