What do I need to fill in on the Store Address page, and where is it used?

Settings → Store Settings → Store Address holds your business contact address. All of these are required: Person Name, Email Id, Phone (with country code), Address, Pincode, Country, State and City.

Type the Pincode first. Wcart looks it up and fills in the country, state and city where it can. Then click Save Changes. If something is missing, the field is marked in red.

The address is used on your printed invoices: open an order and click Print invoice, and your store address appears there if your invoice template includes it.