On this page of the guide to Watch Dogs Legion, you will learn how to go through the first mission in 404 Chapter. Group 404 will contact you and invite you to a meeting.
At the very beginning, go to the place indicated on the map, find the server there, interact with it. Then you listen to the recording, after listening to it, go to a new marker on the map.
Your destination is the Walkie Talkie Club, go inside and use the elevator.
When you use the elevator, you will find yourself on the top floor of the club. Leaving it, turn left and go up. There you will find spider-bots and a ventilation shaft. Open it and take control of the arachnid.
Then go forward from room to room, using the ventilation shafts until you find yourself in the target room, marked with a marker. Make the Spider-bot crawl to the server. Then leave the building.
There are not many enemies, but drones may also appear. You can use force and neutralize opponents with weapons, or use the arachnid.
On the right side at the top, there is a server room, where there is a simple puzzle you need to solve, which consists of switching nodes so that they reach their destination. However, be careful of the red lasers that move there. If they touch you, the alarm will go off.
Connecting all the wires together, go to the main server. Once you get the data from him, leave the building, and the mission will be a success.