Remove date time & author on posts

You would need to edit in the .php files in \wp-content\themes\fifteen and test with trial and error. That is what I did a while ago.

Unfortunately I forgot the details, but they should be easily findable when you google for some phrases within those php files, e.g. “get_sidebar();”.

Forget what I wrote above.

This is how it works:
Dashboard > Appearance > Fifteen Settings > Layout Settings

Add this into the Custom CSS:

.entry-author-link,
.entry-date,
.entry-meta {
	display: none;
}