Giusto per darti un'idea, prova quanto segue, non testato.
<?php
$args=array(
'meta_key'=>'start_date',
'meta_value'=> now(),
'meta_compare' => '>',
'order' => 'DESC',
);
$my_query = null;
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
echo 'List of Posts';
$i=0;
while ($my_query->have_posts()) : $my_query->the_post();
the_title();
$i<2 ? $i++ : break;
endwhile;
}
wp_reset_query();
?>