Make a new Horde character on the PvP ruleset
Forever has no realms: you pick the PvP ruleset when you create the character. Your class and race are set there too, so read which class and which race first.
You need beta access. The opt-in can give it; a pre-purchase of the Epic Pack or the Forever Collection guarantees it.
It must be a brand-new character: one made before the sign-up opened, on September 27 at 11am PT (8pm CEST), does not count, even if it is already level 20. Give it the last name Foreverpvp: the rules require it.
Two locks apply there. An account plays only one faction on the PvP ruleset, so if you already play Alliance there, you need another account or you are out. And the game closes character creation for the faction that outnumbers the other: on September 25, a player on the official forums could not create a Horde character for that reason. If creation is open when you log in, take the chance.
Why not Alliance? At these levels, the Alliance side still causes production problems for the organisers. An Alliance tournament could come at level 60.

