How to grab the first two image attachments from a post?

Looks like you may have just not had a loop setup, try this one

<div class="two_images">
<?php
  global $post;
  $args = array( 
    'post_parent' => $post->ID, 
    'post_type' => 'attachment', 
    'post_mime_type' => 'image', 
    'orderby' => 'menu_order', 
    'order' => 'ASC', 
    'numberposts' => 2 );
   $images = get_posts($args);
   if ( $images ) {
    $i = 0;
    while($i <= 1){
      echo wp_get_attachment_image( $images[$i]->ID, 'full' );
      $i++;
    }
  }
?>
</div>