I can see how it would be helpful to be able to specify the text of the placeholder. I will look into adding that functionality to the plugin.
In the meantime, if you are only using the plugin on one page, you can use a text editor to edit the file /wp-content/plugins/menu-in-post/menu-in-post.php and replace this line (line 76):
$args['items_wrap'] = $select . '<option value="#">' . esc_html(__('Select...', 'menu-in-post')) . '</option>%3$s</select>';
with this:
$args['items_wrap'] = $select . '<option value="#">' . esc_html(__('Racial Equity Resource Guide', 'menu-in-post')) . '</option>%3$s</select>';
That will change the placeholder everywhere you use a Menu-In-Post shortcode to “Racial Equity Resource Guide.” Your changes will be overwritten the next time I update the plugin, but it will get you what you want now, and maybe I can add a setting to change the placeholder text soon.
If you’re using the plugin in more than one place, that won’t help you, unfortunately.
Keep an eye on the changelog of the plugin when I release an update to see if I’ve added the feature, and you can then modify your shortcode to incorporate the setting so it won’t be overwritten in future updates.
I’ll try to post here to notify you when I have the feature added.