Use the spell "Teleport: Moonglade" to travel to Moonglade. When you arrive, speak with Dendrite Starblaze in the village of Nighthaven.
All druids are welcome in the sacred lands of Moonglade, regardless of the current tensions in the Cenarion Circle between Arch Druid Staghelm and Keeper Remulos - Moonglade's guardian. Now that you're learning the ways of the Claw, I'll teach you the spell that lets you transport yourself there. Cast it whenever you seek Moonglade's knowledge or solace.
As for your first lesson, travel to Moonglade and speak with Dendrite Starblaze in Nighthaven about the path you're now on. Good luck, young druid.