Speak to High Priestess Laurena in Stormwind.
You've caught the attention of our superiors, [player]. They've asked you travel to the Cathedral of Light in Stormwind as soon as possible. Apparently they feel you've proven yourself already and are prepared to further your training. When you get there, find High Priestess Laurena. She will be able to guide you further. Good luck, and may the Light be with you.