I want to remove the author details below the single post.

Hi,

You can remove the Single Post Author Box using Edit with tagDiv Composer with a right-click you can delete => https://i.imgur.com/BnhhxVh.png , or selecting the element and with drag & drop place into the deleting red zone from the bottom right of the page => https://i.imgur.com/vkQVCjn.jpg the same for comments.

Thank you!