Try this code
<div class="container">
<!-- Example row of columns -->
<div class="row front-posts">
<?php if ( have_posts() ) : ?>
<?php while ( have_posts() ) : the_post(); ?>
<div class="line2"></div>
<?php endwhile; ?>
<?php endif; ?>
<?php wp_reset_query(); ?>
<!-- Start latest post -->
<div class="line2">
<?php
$paged = get_query_var('paged') ? get_query_var('paged') : 1;
$args = array('post_type' => 'post','cat'=> 2,'posts_per_page' => 9, 'paged' => $paged); // Here 2 ('cat'=>2) is the Id of category of post that need to show
$loop = new WP_Query( $args );?>
<?php while ( $loop->have_posts() ) : $loop->the_post(); ?>
<div class="blog_thumb_wrapper">
<?php
$thumbnail_id = get_post_thumbnail_id();
$thumbnail_url = wp_get_attachment_image_src( $thumbnail_id, 'thumbnail-size', true );
$thumbnail_meta = get_post_meta( $thumbnail_id, '_wp_attachement_image_alt', true );
?>
<a href="https://wordpress.stackexchange.com/questions/230877/<?php the_permalink(); ?>"> <img src="<?php echo $thumbnail_url[0]; ?>" alt="<?php echo $thumbnail_meta; ?> " class="fontpage_thumb"></a>
<div class="carousel-caption sml-blogpost">
<div class="carousel-caption-text blogpost-text">
<a href="https://wordpress.stackexchange.com/questions/230877/<?php the_permalink(); ?>"><p><?php the_time('l, F jS, Y'); ?></p><br>
<h2><?php the_title(); ?></h2><br></a>
</div>
</div>
</div>
<?php endwhile; ?>
<?php wp_reset_query(); ?>
<!-- End latest post -->
</div>
</div><!-- #content -->
Don’t forget to change the category id (‘cat’=> 2). Replace 2 with your category id of post that you want to show