Automatically create a post for each user on wordpress site - wordpress

Question

I'm trying to automatically great a custom post (users) upon registering a new user to my site. I'm just barely familar with php, but I've been working off another question from stackoverflow: Automatically create a post for each user using wp_insert_post
I would ideally love to create a page upon registering or updating user information that carries over custom fields. I've used ACF to create custom fields associated with users (listed in the code as lowercase variables) and custom fields associated with the to be created custom posts (listed in the code as uppercase variables).
Thank you for any help you can offer!
function create_authors_page( $user_id ) {
$the_user = get_userdata( $user_id );
$new_user_name = $the_user->user_login;
$PostSlug = $user_id;
$PostGuid = home_url() . "/" . $PostSlug;
$member_bio = get_field('member_bio');
$contact_info = get_field('contact_info');
$member_affiliation = get_field('member_affiliation');
$my_post = array( 'post_title' => $new_user_name,
'post_type' => 'users',
'post_content' => '',
'post_status' => 'publish',
'post_theme' => 'user-profile',
'guid' => $PostGuid );
$NewPostID = wp_insert_post( $my_post );
$Member_Bio = $member_bio;
$Contact_Info = $contact_info;
$Member_Affiliation = $member_affiliation;
update_post_meta( $NewPostID, $Member_Bio, $Contact_Info, $Member_Affiliation );
return $NewPostID;
}
add_action('publish_members', 'create_authors_page');

Answer 1

Your hook is incorrect, use user_register action hook which fires after a user has registered and passes $user_id as a variable:
add_action('user_register', 'create_authors_page');
function create_authors_page( $user_id ) {
// do your stuff
}
You can also use profile_update hook that trigger each time user update profile.