Most of the choices when creating a product are straightforward.
Products can belong to more than one category.
The short description is what will show on the category listing page.
The long description will be shown on the product page, and each of the product-in-location pages, e.g. Accounting Services in London.
Now this is spun text, which means you will have various paragraphs in your description, with 2,3 or however many variations of that paragraph so that you're varying your content.
The structure is like this:
[["First paragraph, version 1", "First paragraph, version 2", "First paragraph, version 3"], ["Second paragraph, version 1", "Second paragraph, version 2", "Second paragraph, version 3"], ]
and so on. You can of course just have one version of the text, but you have to keep [[" at the beginning, and "]] at the end.