What the achievement asks
Complete the quest Suffusion Camp. Five points.
Blizzard ties this one to the character, so an alt who clears the camp does not close it for your main.
One quest, once. The only hard part is finding it, because nothing in your log points at it.
Where to look
Open your map and find the Fyrakk Assault. Its icon is a large silver dragon head outlined in red, and it sits on whichever zone the assault is currently attacking.
Fly there and the quest giver is at the assault itself, offering Suffusion Camp. Players describe the giver as a large green dragon, standing where the assault begins.
Fyrakk Assaults rotate between the Dragon Isles zones, so the coordinate changes: one week it is in the Ohn'ahran Plains, the next somewhere else. The map icon is what you follow, not a fixed spot.
What the quest wants
You clear one of the Suffusion Camps that the assault has set up. It is public content, designed for whoever is passing, and the assault normally has people in it.
The assault runs on its own schedule rather than being permanently up. If the icon is not on your map, the assault is not running and there is nothing to do but come back. When it is up, this takes a few minutes, so do it the first time you see the icon rather than remembering it later.
Where it fits
Part of A World Awoken. The same assault carries the rest of its own objectives, so a single visit while the icon is up is worth more than the one quest.