Remove Author from below post Caspar Theme

The easiest way is to add this to your theme’s style.css file:
section.author { display: none; }

The disadvantage of that is you’ll need to re-add it if/when you upgrade your theme.
Better to have a child theme and make your css edits there: https://codex.wordpress.org/Child_Themes

Or use the Jetpack plugin and activate the Custom CSS feature: https://jetpack.com/support/custom-css/