Display posts side by side with custom query

Not sure how your final html should look, but I guess it’s:

<ul>
    <li>...</li>
    <li>...</li>
    <li>...</li>
</ul>

In that case, you should move the ul element outside the while loop and your code should look like this:

<ul>
<?php while ($agendaHome->have_posts()) {
            $agendaHome->the_post(); ?>
    <li>rest of the code goes here</li>
<?php } ?>
</ul>

Also add apostrophes around ASC at the order parameter.

'order' => 'ASC'