New Wordpress Template page based off existing page

I have a template page that currently pulls all posts (in this template called "cases") I only want it to pull specific case categories. Not all the categories. Looking for someone to build the same exact template page but modify the code so that I can enter manually the specific 'case_category' that I want, not every category. <?php $args = array( 'orderby' => 'date', 'order' => 'DESC', 'posts_per_page' => -1, 'paged' => 1, 'post_type' => 'osetin_case' ); $osetin_query = new WP_Query( $args ); if ( $osetin_query->have_posts() ) { while ( $osetin_query->have_posts() ) : $osetin_query->the_post(); $terms = get_the_terms(get_the_ID(), 'case_category'); $term_name = $terms[0]->name; ?>