merhaba hocam, şuradaki adreste detaylı bilgi var sanırım:

https://codex.wordpress.org/Function_Reference/get_currentuserinfo

ayrıca google'da alternatif bilgilere ulaşabilirsiniz: "wordpress user info"

get_currentuserinfo();

echo 'Username: ' . $current_user->user_login . "\n";
echo 'User email: ' . $current_user->user_email . "\n";
echo 'User level: ' . $current_user->user_level . "\n";
echo 'User first name: ' . $current_user->user_firstname . "\n";
echo 'User last name: ' . $current_user->user_lastname . "\n";
echo 'User display name: ' . $current_user->display_name . "\n";
echo 'User ID: ' . $current_user->ID . "\n";
?>