To start the quest, go to the location on the picture shown above. There will be an entrance to a small ruin with a Geo pillar and a man standing there. Talk to Vermeer to get the quest.
The two quest items are quite close to the teleport waypoints, so it's pretty easy to get if you've enabled them both.
The first one is to the west of the teleport waypoint in the small ruins shown above. Not quite near the edge, but you will see a sparkle in the ground near the wall.
Second on is to the right of the west teleport waypoint, and it's in the bush on the left of the picture.
The rocks that you'll need to find are in the small ponds area. In case you need to interact with all of them, here are all the locations that you can interact.
After you get the rocks, talk to Vermeer again to get to the next part of the quest.
Climb to the head of both the statues nearby, and place the rocks there.
Talk to Vermeer again and the seal for the Geo pillar will unlock. Activate it and some enemies will appear. Once you clear them out, you can go inside the ruin and get some treasures.
Puzzles, Secrets, and Hidden Chests in Dragonspine
Puzzles, Secrets, and Hidden Chests in Liyue
Staff of Homa