Take a look at the Starter Kit (it's the best way to try Kirby): https://github.com/getkirby/starterkit
Look inside the /content and /site/templates folders.
So this logic can go on a template or snippet:
<?php $latest = page('blog')->children()->visible()->limit(6); ?>
<div class="widget">
<?php foreach($latest as $post) : ?>
<a href="<?= $post->url()?>"><h2><?= $post->title()->html() ?></h2></a>
<?php endforeach ?>
</div>