Praying at Auriel's Shrine in the temple or back in the cave with the first teleporter will give you a blessing that boosts your archery quite a bit for a very long time - longer than most holy shrines anyway. There are 2 shellbugs in the game. The first is in a cave in the big grassy area you find yourself upon first entering the Vale.
i am at the forgotten vale portal (according to the map) where a snow elf ghost is saying that some gods brilliance will illuminate my path and i take the water from the shrine next to him then i have no idea where to go . is this a bug is something meant to happen when i take the water because all i got was a quest update