In case you were looking for the Google Merchant Centre product categories, here is the full list:
https://www.google.com/basepages/producttype/taxonomy-with-ids.en-US.txt
This should help you find the google category # you need to enter in Shopify.
Ps. If you make your own products, don't forget to list the products as "custom" (or else you'll need to enter a GTIN/barcode number).
More social media for personal online business reads: