Getting most recent post in WordPress have builtin function named
  wp_get_recent_posts( $args, $output ). so let's try with this function to get most recent 5 post
$args = array( 'numberposts' => 5, 'offset' => 0, 'category' => 0, 'orderby' => 'post_date', 'order' => 'DESC', 'post_type' => 'post', 'post_status' => 'publish', 'suppress_filters' => true ); OR $args = array( 'numberposts' => '5' );

$recent_posts = wp_get_recent_posts($args); foreach( $recent_posts as $recent ){ echo '<li><a href="' . get_permalink($recent["ID"]) . '">' . $recent["post_title"].'</a> </li> '; if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it. the_post_thumbnail('thumbnail'); } } Here thumbnail, medium, large, full is image size for more Click But Other few way you can get you post details like
1- Loop with get_posts() 2- Loop with query_posts() 3- Loop with WP_Query()
 

• To modify the default loop, use query_posts()
• To modify loops and/or create multiple loops, use WP_Query()
• To create static, additional loops, use get_posts()

But Best way to customize query post is WP_Query()
 <ul> // Define our WP Query Parameters <?php $the_query = new WP_Query( 'posts_per_page=5' ); ?>

        // Start our WP Query
        <?php while ($the_query -> have_posts()) : $the_query -> the_post(); ?>

            // Display the Post Title with Hyperlink
            <li><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></li>

            // Display the Post Featured Image
            <li><?php
                if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
                    the_post_thumbnail('thumbnail');
                } ?></li>

            // Repeat the process and reset once it hits the limit
            <?php
        endwhile;
        wp_reset_postdata();
        ?>
    </ul>

if you want to learn more then go there :Click
and Click

Thanks Musa

Getting most recent post in WordPress have builtin function named wp_get_recent_posts( $args, $output ). So let's try with this function to get most recent 5 post

$args = array(
    'numberposts' => 5,
    'offset' => 0,
    'category' => 0,
    'orderby' => 'post_date',
    'order' => 'DESC',
    'post_type' => 'post',
    'post_status' => 'publish',
    'suppress_filters' => true );

OR

$args = array( 'numberposts' => '5' );

$recent_posts = wp_get_recent_posts($args);
    foreach( $recent_posts as $recent ){
        echo '<li><a href="' . get_permalink($recent["ID"]) . '">' .        $recent["post_title"].'</a> </li> ';
if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
    the_post_thumbnail('thumbnail');
}
    }

Here thumbnail, medium, large, full is image size for more Click But Other few way you can get you post details like

1- Loop with get_posts() 2- Loop with query_posts() 3- Loop with WP_Query()

• To modify the default loop, use query_posts()
• To modify loops and/or create multiple loops, use WP_Query()
• To create static, additional loops, use get_posts()

But Best way to customize query post is WP_Query()

<ul>
        // Define our WP Query Parameters
        <?php $the_query = new WP_Query( 'posts_per_page=5' ); ?>`

        // Start our WP Query
        <?php while ($the_query -> have_posts()) : $the_query -> the_post(); ?>

            // Display the Post Title with Hyperlink
            <li><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></li>

            // Display the Post Featured Image
            <li><?php
                if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
                    the_post_thumbnail('thumbnail');
                } ?></li>

            // Repeat the process and reset once it hits the limit
            <?php
        endwhile;
        wp_reset_postdata();
        ?>
    </ul>

if you want to learn more then go there :Click
and Click

But Best way to customize query post is WP_Query().

<ul> ` // Define our WP Query Parameters

     `   // Start our WP Query
        <?php while ($the_query -> have_posts()) : $the_query -> the_post(); ?>

            // Display the Post Title with Hyperlink
            <li><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></li>

            // Display the Post Featured Image
            <li><?php
            if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
                the_post_thumbnail('thumbnail');
            } ?></li>

            // Repeat the process and reset once it hits the limit
            <?php
        endwhile;
        wp_reset_postdata();
        ?>
    </ul>`

But Best way to customize query post is WP_Query()  
<ul> // Define our WP Query Parameters <?php $the_query = new WP_Query( 'posts_per_page=5' ); ?>

        // Start our WP Query
        <?php while ($the_query -> have_posts()) : $the_query -> the_post(); ?>

            // Display the Post Title with Hyperlink
            <li><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></li>

            // Display the Post Featured Image
            <li><?php
                if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
                    the_post_thumbnail('thumbnail');
                } ?></li>

            // Repeat the process and reset once it hits the limit
            <?php
        endwhile;
        wp_reset_postdata();
        ?>
    </ul>