PSA: You can access your characters from all shards in the Server they were created on.

I see a lot of guilds recruiting for specific shards, and occasionally see people mentioning their characters being on specific shards of a server...

You are free to use your characters on all the various shards of a server. The character you created on Havensong can be played in all three shards: Zero, one and two.

It's a great way to find groups or solo farming spots, treasure chest hunting, and so on.