Using both ‘One Column’ and ‘Two Column’

Hi, I created my child theme and page template but I don’t see any one/two column option in the page text.

Please could you assist?

——————————————————————————–
<?php
/*
* Template Name: OneColumn
*
*
* @package WordPress
* @subpackage Twenty_Seventeen
* @since Twenty Seventeen 1.0
* @version 1.0
*/

get_header(); ?>

<div class=”wrap”>
<div id=”primary” class=”content-area”>
<main id=”main” class=”site-main” role=”main”>

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

get_template_part( ‘template-parts/page/content’, ‘page’ );

// If comments are open or we have at least one comment, load up the comment template.
if ( comments_open() || get_comments_number() ) :
comments_template();
endif;

endwhile; // End the loop.
?>

</main><!– #main –>
</div><!– #primary –>
</div><!– .wrap –>

<?php
get_footer();

——————————————————————————–

When you go to appeareance/customize/theme_options there is a ‘one column’ or ‘two column’ distribution option for the whole website, on twentyseventeen design.

I would like to leave ‘two column’ distribution activated and then cancel it for some pages. It seems the ‘one/two column’ design is not coded in the page.php file but somewhere else where it affects the whole web.