Get Users Post ID

by

I am surprised that you didn’t find references to the two components that you need. These are both extremely common.

$current_user = wp_get_current_user();
$query = new WP_Query( 
  array (
    'author' => $current_user->ID,
    'posts_per_page' => 1,
    'post_status' => array('any'),
  )
);
var_dump($query); // debug

Reference:

http://codex.wordpress.org/Function_Reference/wp_get_current_user
http://codex.wordpress.org/Class_Reference/WP_Query