SeaBerGBer on "Single Post Type"

I am trying to have category pages that display only one category of post. I realize this has been brought up many times but there always seems to be a different answer and none of them seem to be working. I have successfully done this on another theme in the past and my new one is not behaving the same at all. I made a new template file and copied my index information into it. The index code looked like this:

<?php get_header() ?>

  <section class="section" role="main">

    <?php echo ace_breadcrumb(); ?>

    <?php if (have_posts()) : while (have_posts()) : the_post(); ?>

      <?php get_template_part('loop'); ?>

    <?php endwhile; ?>

      <section class="pagination">
        <p><?php echo get_pagination_links(); ?></p>
      </section>

    <?php else : get_template_part('none'); endif; ?>

  </section><!-- .section -->

  <?php get_sidebar(); ?>

<?php get_footer(); ?>