9th Dawn III

The first opponent you can find to play Fyued against is Wolten in the first town, Ashwick. He's in the top left of the open area you get to upon entering. You will not have enough cards to play, but you can buy enough from him for 200 gold.

Beat him once to win. The rules are explained to you, but its basically a variation on Top Trumps. You both have basic cards, so you could probably win just by placing cards anywhere and getting lucky.