If tag x then show y + tag name(s)

you can use the get_the_tags function, something along the lines of:

$posttags = get_the_tags();
if ($posttags) {
    echo (count($posttags) > 1) ? 'Tags: ' : 'Tag: ';
    $links = array();
    foreach($posttags as $tag) {
        $links[] = sprintf('<a href="https://wordpress.stackexchange.com/questions/255261/%s">%s</a>',  get_tag_link($tag->term_id), $tag->name);
    }
    echo implode(', ', $links);
}

Reference: https://codex.wordpress.org/Function_Reference/get_the_tags