Hey friend, settlers of elyria had a rough start and they are revamping it and starting over soon with a newer map style. So in short, you didn't miss it. You will be able to see the domains for sale here though when it starts back up.
https://chroniclesofelyria.com/domains#/
When the event starts again, you will need a bloodline or higher pledge package to participate in the sale of domains and settlements as exposition access is required and bloodline is the lowest pledge package to get you expo access.
You will also have to purchase every tier under the one you are buying. So if you want a duchy, you first need a county and a settlement as well. You can learn more about the event here.
https://chroniclesofelyria.com/blog/34438/Welcome-to-the-Settlers-of-Elyria-Event
Just as an aside, this isn't buying individual parcels in game, we are still a ways off from doing that. This is just domains and settlements. People with intent to claim specific land for themselves in game still have a bit of a wait yet.
edit: Also as an aside, once the event starts back up sale of domains is expected to continue until further into development, or they are all claimed. So the end of the 45 day event doesn't mean the end of your chance to get a domain, although by then I expect most the popular choices will be gone :P
