Although the Responders are long gone from Flatwoods, their automated courses still remain active and can be used by Vault 76 dwellers to become officially certified Volunteers. The first step can be taken in Flatwoods, where volunteers need to first help complete Kesha McDermott's water tests.
This is a tutorial quest introducing the basics of survival. The player has to first find Kesha's body over by the river, curled up on the bank. Her location can also be obtained from the self-serve kiosk, after accessing the people's directory.
There will be a water test kit on her body. The player has to sample two locations, one at the river nearby, the other at the water pumps located at the edge of town, near the farms. Simply drinking water from each source will collect a sample.
Then it's a matter of returning to the church and uploading the sample to Kesha's terminal over behind the automated vendor. This will lead to the conclusion that water must first be boiled to be made potable. Then the quest asks the player to gather wood and two units of dirty water, then use any cooking station to make boiled water.
Then it's a matter of turning the quest in at the kiosk. Halfway through to Volunteer status!
Locate Kesha McDermott
(Optional) Search for her location in the system
Search for Kesha along the nearby river
Retrieve the Water Testing Kit from Kesha McDermott
Test a sample of water from the river
Test a sample of water from Flatwood's Water Pumps
Analyze the Water Testing Kit's results in Kesha's lab