Store setup fields
What each field on Store setup does, for every platform.
What to fill in
On Store setup you can supply the same things a Shopify connection would discover: the URL of your product feed, a product page or two, where your basket and checkout live, and — if you want the transactional tests — the id of one in-stock product and one out-of-stock one.
Nothing here is required. Anything you leave out means the tests that needed it are skipped with a reason, not failed.