limit number post per page

here is my query

    <?php
        $my_query = new WP_Query();
        $query_posts = $my_query->query($args);
       
        $my_query1 = new WP_Query($args);
        $pages = $my_query1->max_num_pages;
            if(!$pages)
                $pages = 1;

        while ( $my_query->have_posts() ) :
                  $my_query->the_post();

        $params = array('pid'    => get_the_ID(),
                        'do'    => 'delete');
        $private_download = array('file_name'    => $nmfilemanager -> get_attachment_file_name( get_the_ID() ),
                                   'do'            => 'download');

        $urlDelete = $nmfilemanager -> fixRequestURI($params);
        $urlPrivateDownload = $nmfilemanager -> fixRequestURI($private_download);       
    $meta = get_post_meta(get_the_ID(), '_wp_attachment_metadata', true);
    $file_meta = json_decode($meta, true);
    ?>

PHP:

 

try this, But I'am not sure if it will work with your query..

<?php

   $args = array(                                   
                       'showposts' => 16, // Change the number to the number of post you want to show                                   
                );

        $my_query = new WP_Query($args);          
        $pages = $my_query1->max_num_pages;
            if(!$pages)
                $pages = 1;

        while ( $my_query->have_posts() ) :
                  $my_query->the_post();

        $params = array('pid'    => get_the_ID(),
                        'do'    => 'delete');
        $private_download = array('file_name'    => $nmfilemanager -> get_attachment_file_name( get_the_ID() ),
                                   'do'            => 'download');

        $urlDelete = $nmfilemanager -> fixRequestURI($params);
        $urlPrivateDownload = $nmfilemanager -> fixRequestURI($private_download);      
    $meta = get_post_meta(get_the_ID(), '_wp_attachment_metadata', true);
    $file_meta = json_decode($meta, true);
    ?>

Code (markup):

 

thanks sir, it work......