You absolutely can, however, you do not need to do so. LunarCon is designed so that you can enjoy all happenings via Discord and Twitch streams that are hosting the event. The most important place to be would be Discord!
You would need housing unlocked in all areas (Ul'dah, Gridiania, Limsa, and Shirogane) to be safe as LunarCon will be happening across several plots of land in the housing areas of Brynhildr.
Everything for the LunarCon will be taking place on Brynhildr server in Crystal Data Center.
All you need to do is submit a new form! This will overwrite your previous entry. Your latest submission will be the one we consider.