My new WordPress theme based on the TwentyEleven theme doesn’t display the front page OR the blog page

First of all Create Template and Assign Template to Static page to which u have to display as a home page. Example of template:

<?php
/**
* Template Name: Home Page Template
*
*/
get_header();
?>
<div class="mid-part cm-fl">
<div id="container">
<div id="content" role="main">
<div class="left-section">
<?php if ( have_posts() ) while ( have_posts() ) : the_post(); ?>
<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<div class="body-top"></div>
<div class="entry-content body-content">
<h2 class="entry-title"><?php the_title(); ?></h2>                  
<?php the_content(); ?>                 
</div>
<div class="body-bottom"></div>
</div>

<?php endwhile; ?>
</div>
</div>
</div>
<?php get_sidebar(); ?>
</div>
<?php get_footer(); ?>