How to sort or order gallery category?

You can change and order categories by title, date, alphabet, or random.

If you want to order it, example by ID,

please follow this step: 

Open theme folder/page-work.php line 15, 
add this below taxonomy category:

'orderby' => 'id',

example by random, Here you go:

Open theme folder > page-work.php line 15,
add this below taxonomy category:

'orderby' => 'rand',

Beside that, you can read the instruction from this link:
https://codex.wordpress.org/Class_Reference/WP_Query

Have a try. Cheers :)