wordpress get post taxonomy terms

// RETRIVE TERM SLUG ( for single.php or template-part )

$terms = get_the_terms( $post->ID, 'your-taxonomy' );
if ( !empty( $terms ) ){
    // get the first term
    $term = array_shift( $terms );
    echo $term->slug;
}

<?php
     $taxonomy = 'my_taxonomy'; // this is the name of the taxonomy
     $terms = get_terms($taxonomy);
     $args = array(
        'post_type' => 'post',
        'tax_query' => array(
                    array(
                        'taxonomy' => 'updates',
                        'field' => 'slug',
                        'terms' => wp_list_pluck($terms,'slug')
                    )
                )
        );

     $my_query = new WP_Query( $args );
     if($my_query->have_posts()) :
         while ($my_query->have_posts()) : $my_query->the_post();

              // do what you want to do with the queried posts

          endwhile;
     endif;
  ?>

$term = get_term_by( 'slug', get_query_var( 'term' ), get_query_var( 'taxonomy' ) );
echo $term->name; // will show the name
echo $term->slug; // will show the slug