A listing is what a buyer reads before they decide whether to care. Here is each field and what it actually does.
Title
The words a buyer would type. Brand, item, size, condition — in that order. How to write one.
Photographs
Daylight, plain background, and the shots that prevent arguments: the back, the label, the flaw. How.
Description
What it is, what is good about it, what is wrong with it, what is included, and how it will travel.
The two things sellers leave out, every time: measurements and the flaw. Both cost you money. Why naming the flaw raises the price.
Price
A starting price, and optionally a reserve. How to choose.
Delivery
Each listing carries its own delivery option. A scarf and a framed piece of glass are different problems and should not share a setting. Set this up before you start listing.
Quantity
One of a kind, or several of the same thing. Several changes how it behaves in a show. Keeping stock straight.
Questions people ask
How many photographs should I add?
Enough that nobody has to ask. For anything with condition, that is more than three.
Can I edit a listing after publishing?
Before bidding starts, freely. Once an auction is running, no — people have bid on what it said.
Why is my listing not showing?
Usually still a draft, or in the wrong category. Check both before assuming something is broken.
Do I need a photo if I am showing it live?
Yes. The listing outlives the show.
Next: writing a title.