Example
The simple yet important lines are
'paged' => get_query_var('paged', 1), //1 is fallback if wp cannot find the page number dynamically
AND
'total' => $pastEvents->max_num_pages,
$max_num_pages // The total number of pages. Is the result of $found_posts / $posts_per_page. https://developer.wordpress.org/reference/classes/wp_query/#properties
$evts = new WP_Query(array(
'paged' => get_query_var('paged', 1), //1 is fallback if wp cannot find the page number dynamically
'posts_per_page' => 1, //show 1 post per page
'post_type' => 'event',
));
while($evts->have_posts()) {
$evts->the_post(); ?>
<p> <?php the_title() ?> </p>
<p> <?php the_content(); ?> </p>
<?php }
echo paginate_links(array(
'total' => $evts->max_num_pages,
));
?>