Hi,
If you want to see the portfolio page first when you enter the website,
Please go to settings > reading > choose your front page as portfolio.
If you like to change the menu position, then go to appearance > widgets > empathy template page and change the position.
Thanks

Hi,
It is not possible by default but you can try to use this plugin to change the order of the tabs.
https://srd.wordpress.org/plugins/taxonomy-terms-order/

For your second question, you should install and run this plugin;
https://wordpress.org/plugins/insert-headers-and-footers/
and add this script code;

<script>
(function($) { "use strict"; 
   setTimeout(function() { $('#filters li').eq(1).find('a').trigger('click')}, 1000);
})(jQuery);
</script>

Thanks

Hi,
You can ask to plugin’s author. You can organize your order via this plugin.
https://wordpress.org/support/plugin/taxonomy-terms-order
Thanks