OK so was way simpler than I thought in the end and didn’t involve a query of query.
The same can be achieved like this:
/*GETING THE USERS FIRST PUBLISHED SUBSCRIPTION?? */
$useremail = $ticket['email'];
$user = get_user_by( 'email', $useremail );
$IDuser = $user->ID;
$args = array(
'posts_per_page' => 1,
'post_type' => 'subscription',
'author' => $IDuser,
'meta_key' => 'state',
'meta_value' => 'complete',
'orderby' => 'date',
'order' => 'ASC',
);
$first_post = new WP_Query($args);
// '<pre>'.print_r($first_post).'</pre>'; // You can use this to check what the query produces to make sure you're on the right track.
if ($first_post->have_posts()) {
$first_post->the_post();
the_time('M j, Y');
wp_reset_postdata();