When a user is created in the Evvnt system it is assigned to a site that is the "owner" of that user. This determines where we will send your event when you post for free, and where we will feature your event when you upgrade to premium. See more here: How does Evvnt post your event?
If you find that you have a user assigned to a site that is no longer relevant to your situation, you can submit a request here to have your user assigned to another site. This will make it easier to post to the same site with all your events.
You can post to other sites even if your user is assigned to somewhere else. See more here: Can I post to a different publication for my events?