Hiding title of selected post without plugins

If there is only 1 post showing up in your page, you could use the the_title() filter to hide the title.

The simplest way would be this:

function hide_my_title( $title, $id = null ) {

    if ( is_single( 2 ) ) {
        return '';
    }

    return $title;
}
add_filter( 'the_title', 'hide_my_title', 10, 2 );

This will hide the title when you are viewing the post with an ID of 2. Notice, this might also hide the title for another posts if some elements such as related posts are being used on this page.