How to display custom post type only on a certain page?

Very difficult to answer given the information provided but you probably want …

'has_archive'   => false,
'rewrite' => array('slug'=>"https://wordpress.stackexchange.com/",'with_front'=>false),

… as part of your arguments when you register the post type and then you can add the post type to the main query for that home/front page…

function add_cpt_to_home($qry) {
  if (is_front_page() || is_home()) {
    $post_type = (array)$qry->get('post_type');
    $post_type[] = 'post';
    $post_type[] = 'project';
    $post_type = array_unique(array_filter($post_type));
    $qry->set('post_type',$post_type);
  }
}
add_action('pre_get_posts','add_cpt_to_home');

Or write a secondary query to pull that post_type.

$args = array(
  'post_type' => 'project'
);
$projects = new WP_Query($args);
if ($projects->have_posts()) {
  while ($projects->have_posts()) {
    $projects->the_post();
    the_title(); // etc
  }
}

Not tested very well, but as I said it is hard to answer given the information provided.