How do I change my shop's name and subtitle?

Short answer: On a draft, click straight on the title or the subtitle shown at the top of the shop and type your own. Changing the title also updates the shop's address, as long as that address has not been customized yet.

Steps

On the “Shops” page, open a draft — a live shop cannot be modified directly (orange “Modify the shop (create a draft)” button).
Click the title shown at the top of the shop and type your organisation's name.
Click the subtitle — “The official shop” by default — and replace it if you want to.
Save, then put the draft into service.

The default title blocks putting the shop into service

A demo shop arrives with the title “Shop title”. Until that title has been replaced, the shop's address stays locked and putting the shop into service is refused: the blue button is grayed out and its tooltip reads “Change the shop title first”.

That is deliberate — a shop still called “Shop title” has no presentable address. So the title is the first thing to change.

As long as the address has not been customized, it follows the title: renaming the shop rebuilds the subdomain from the new name. See How do I set my shop's address.

What to put

The title is the name your community knows you by — the organisation's name, not a description. It appears at the top of every page of the shop, next to the logo.

The subtitle is a short line under the title. “The official shop” suits most cases; a section, a season or a team can usefully replace it when you run several shops.

Going further

How do I put my logo in my shop header — the other half of the header.
How do I choose my shop's two colors

You'll know it worked when: The shop shows your organisation's name as its title, and the subtitle you chose just below it.