The inaugural quest for Acadia begins after you meet DiMA, the leader of the synths at Acadia. He's opened up the compound to you and suggests finding Faraday or Chase if you wish to help the Acadians.
Speak to Chase and offer your help. Chase will fill you in on a new synth that has gone missing while in transit to Acadia. Ask her for any leads she may have, and she will suggest talking to Brooks in Far Harbor. Chase will offer up the information that Brooks is a synth that helps with new arrivals, and to use his designation, L7-92, should he need any convincing to help. Finish the conversation to trigger The Arrival.
Find Faraday to offer your assistance. He will brief you on a boat along the coast of the island about a boat transporting storage drives that never completed its journey and is wrecked southwest of Acadia. A speech check will reveal Faraday is unsure what happened to the boat, but that it lost a synth on the journey. Accept the quest to start Data Recovery.
Report your successes about Faraday and Chase's tasks to complete the quest.