The Vaelwarden
In Guild Wars 3 you play a Vaelwarden. The official site describes the role as a guardian of the land of Orr, protector of the people and spirits that call Orr home.
Your role
ArenaNet frames the Vaelwarden as a member of a guild of adventurers committed to preserving and protecting both the spirits of the wild and the land of Orr itself. That ties the player fantasy straight to the setting: you are not a passing hero, you belong to Orr and answer for it.
The studio has pointed to character customization and skill building as part of how you make a Vaelwarden your own, though it has not shown the systems behind that yet.
The Seeker
Every Vaelwarden has a Seeker. ArenaNet describes it as both a connection to the spirits of Orr and a mount. So the Seeker is two things at once: a story link to the spirits you protect, and the creature you ride as part of the momentum movement system.
Mounts were one of Guild Wars 2’s most liked additions. Building one into Guild Wars 3 from the start, and making it core to both travel and the world’s spirits, is a clear step on from that. Read how riding fits the wider movement on the gameplay page.
Still unknown
ArenaNet has not said whether Vaelwardens split into professions or classes, how skills and builds work, or how much you can change the Seeker. Those details are expected in later reveals. For the sourced facts so far, see what we know.