Add product in Shopify and sync to Transdirect Shipping App
Your website is created in Shopify and now you realise you're best off learning how to (at least) upload a product for yourself.
I am in no way affiliated with Shopify or Transdirect Shipping - although these instructions are specific to them.
Here are easy-to-follow instructions to:
add a product listing
categorise it and add tags
set up your SEO
and, sync it with your Transdirect shipping app for automated shipping calculator at check-out