What the achievement asks
Complete the quest Shaping the Dreamsurge. Five points.
This one is tied to the character rather than the account, so do it on whichever character is chasing the meta.
One quest, once. This is one of the shortest achievements in the expansion, and the only thing to know is where to be.
The Dreamsurge moves every week
The Dreamsurge is a weekly event that settles in one of the four original Dragonflight zones at a time: The Waking Shores, the Ohn'ahran Plains, The Azure Span or Thaldraszus. It moves on the weekly reset.
Archdruid Hamuul Runetotem gives the quest, and he stands wherever the Dreamsurge currently is, so there is no fixed coordinate to give you. Open your map: the active Dreamsurge is marked on the zone it has landed in, and Hamuul is at the centre of it.
What the quest wants
Shaping the Dreamsurge is the event's weekly, and it is finished by taking part in the Dreamsurge activities in that zone until the quest completes. There is no group requirement, no timer within the week, and nothing that can be failed.
Because it is weekly, the only way to be late is to be away for the whole week. If you are working through the meta and see the Dreamsurge active, do this quest immediately rather than adding it to a list: it is a few minutes now against waiting for the rotation to bring it back.
Where it fits
Part of the Emerald Dream and Dreamsurge work inside A World Awoken. The zone the Dreamsurge lands in also gets bonus rewards for its ordinary activities that week, so it is a good week to do anything else you still need in that zone.