I can't progress through Vloxen Excavations?

Hey

I wanted to cap Poison Arrow on the 2nd lvl however I found that I couldn't get passed the door onto the 2nd lvl. I think I'm doing something wrong, but I don't know what. Also, entering it from Vlox's Falls and killing the 2-3 groups of monsters, I found after that there was no area map like I thought there was supposed to be.
Am I doing something wrong, or..?

Yes. You're doing something wrong, but no biggie. In order to pass through to level 2 of Vloxen excavations, you have to take the quest "Dredging the Depths" from Molenin in Umbral Grotto. The main entrance to the Vloxen dungeon is also accessed from Umbral Grotto if you want to get the dungeon map. You can enter the dungeon from Vlox falls as you were doing, but you enter it at a point halfway through the level so you have already passed the dungeon map location if you use that entrance. If you know the layout, you can map to Umbral, get the quest, and then map back to Vlox Falls and use that entrance.