Excluding/removing the author name in posts

Which theme are you using? Can you post a link to your site?

Get a custom CSS plugin and use this code:

.single .entry-footer .byline {
	display: none;
}

Since you appear to be using a caching/optimizing plugin, you’ll likely need to temporarily disable that plugin and flush the cache before you’ll see any changes.

Try

.group-blog .byline {
  display: none;
}