Ordinary accounts can have up to 4 shops/galleries and Gold accounts can have up to 6.

I started off with two shops and two galleries. When I got a six month GA I added an extra shop and gallery so I now have three shops and three galleries.

My GA runs out in a few days so I'll only be able to use two shops and two galleries. Does the site decide which one they'll be or do I get a choice?

You will still be able to use all of them. You won't be able to create any new shops/galleries. So like, if you delete one of them and go down to 5, you won't be able to make a new one until you have a GA again. But you won't lose any you currently have.

Thanks. I tried looking in the FAQ for this kind of information but I might have missed it.