Using WordPress ‘get_the_author_firstname()’ PHP function
Retrieve the first name of the author of the current post.
Posts
Using WordPress ‘get_the_author_ID()’ PHP function
Retrieve the ID of the author of the current post.
Using WordPress ‘get_the_category()’ PHP function
The `get_the_category()` function in WordPress is used to retrieve the categories associated with a post
Using WordPress ‘map_meta_cap()’ PHP function
Maps a capability to the primitive capabilities required of the given user to satisfy the capability being checked.