Well you only have the single copy of jQuery being loaded but it IS an older copy and it IS being loaded improperly by your WP theme. It should be changed. However the site is throwing a script error regardless of that in the themes ‘custom.js’ file – but let’s fix the jQuery load first.
I am guess it is being loaded in the themes functions.php file so take a look to see if your can see a wp_enqueue_script() call in there… Let us know what you find.