Deeper editing of index.php and single.php

hey add the following code in your index.php file to show the three recent blog post like this

 <?php                  
            query_posts(array(
                'post_type'      => 'post',
                'posts_per_page' => 3,
                'order'    => 'ASC',            
            ));
    ?>          

 <?php  if ( have_posts() ) :?>
    <?php while ( have_posts() ) :the_post(); ?>
         <!-- Start BlogItem -->        
            <article id="post-<?php the_ID();?>" <?php post_class();?>>
                 <?php the_post_thumbnail( 'large' );?>
                <header class="entry-header">
                    <h1><a href="https://wordpress.stackexchange.com/questions/173522/<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'blog' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h1>  
            <p class="post_date"><?php blog_posted_on(); ?></p>
                </header><!-- .entry-header -->
            <!-- Start content -->
                      <div class="content"><?php wp_excerpt('post_len','post_readmore'); ?></div>   
                    <!-- This is used to provide More Links-->                        
                    <!-- End content -->
                 </article>
                 <!-- End BlogItem --> 
            <?php endwhile; ?>
            <?php endif;?>

And also add the two function in your functions.php file

   if ( ! function_exists( 'blog_posted_on') ):         
        function blog_posted_on(){
             if ( count( get_the_category() ) ) :                               
                printf( __( 'On %2$s ', 'blog' ), 'entry-utility-prep entry-utility-prep-cat-links', get_the_category_list( ', ' ) );                           
                printf( __( '%2$s <span class="https://wordpress.stackexchange.com/questions/173522/%1$s"></span> <span>writing by</span> %3$s', 'blog'),
                 'meta-prep meta-prep-author',
                  sprintf( '<a href="https://wordpress.stackexchange.com/questions/173522/%1$s" title="%2$s" rel="bookmark"><span>%3$s</span></a>',
                   get_permalink(),
                   esc_attr(get_the_time() ),
                   get_the_date()                       
                ),
                 sprintf( '<span class="author vcard"><a class="url fn n" href="https://wordpress.stackexchange.com/questions/173522/%1$s" title="%2$s">%3$s</a></span>',
                    get_author_posts_url( get_the_author_meta( 'ID' ) ),
                        sprintf( esc_attr__( 'View all posts by %s', 'blog' ), get_the_author() ),
                        get_the_author()
                    )                       
                    );
            endif; 
        }            
  endif;



function wp_excerpt($length_callback = '', $more_callback = '')
        {
            global $post;
            if (function_exists($length_callback)) {
                add_filter('excerpt_length', $length_callback);
            }
            if (function_exists($more_callback)) {
                add_filter('excerpt_more', $more_callback);
            }
            $output = get_the_excerpt();
            $output = apply_filters('wptexturize', $output);
            $output = apply_filters('convert_chars', $output);
            $output="<p>" . $output . '</p>';
            echo $output;
        }

        function post_len($length) {
            return 41;
        }

        function post_readmore($more){
        global $post;
        return '<span class="post-read-more-color"><a href="'. get_permalink() . '">' . __( ' Read more...') . '</a></span>';
        }  

it work fine.