Now that I’m looking at all the code I can tell more.
Fist problem, do not set the meta type to DATE. ACF does not store date fields as a proper MySQL date value. This should either be NUMERIC or CHAR, CHAR it the default so you can remove it or set it to NUMERIC
You need to set meta_key argument in your query if you’re going to use 'orderby' => 'meta_value', setting a meta_query value is not the same as the meta_key argument.
Second problem, this if block is not properly formatted
if ($next_event_query->have_posts())
there’s no colon and no endif statement
The next problem I see is here
$tradeshowslocation = get_sub_field('event_location', 40);
and here
<p class="eventdate"><?php the_sub_field('event_date'); ?><br />
<span class="locplace"><?php the_sub_field('event_location'); ?></span></p>
Inside the loop for your custom query ACF will be looking to get values from the post in the current loop and not the original post. The have_rows() loop in your code is looking at the original post and there is not have_rows() loop for these sub fields, so I’m still not sure where you’re trying to get field values from in your custom query loop.
