<?php
	$my_id = 22; // change to relevant page ID
	$post_id_5369 = get_post($my_id);
	$content = $post_id_5369->post_content;
	$content = apply_filters('the_content', $content);
	$content = str_replace(']]>', ']]>', $content);
	$words = explode(' ', $content);
	$i = 0;
	while ($i <= 20) { 
		$short .= $words[$i] . ' ';
		$i++;
	}
		echo $short;
?>

This gets the content from the page with the ID 22 (change as appropriate on line 1) and echos the first 20 words (change word count on line 8) - can be used on any page inside your Wordpress theme.

echo first 20 words of any page

wordpress

PHP