The game begins with Samus responding to a distress call from the Ceres Station. You'll start out at the top of a long shaft, Drop down past all the platforms and go through the door at the bottom. Head through the next few corridors, eventually you'll find the main control room with bodies of crew members everywhere.
Go through the door at the back of the room to find the Metroid hatchling, just before the giant Ridley appears holding it. Refer to the bosses guide to send Ridley on his way.
Once Ridley escapes with the Metroid, the self-destruct sequence will engage and you'll have exactly 1 minute to escape the station before it blows. Quickly head back out to the control room and through all the corridors back to the main shaft. Watch out for the gas that spews out from the ground and walls, and keep an eye out for falling debris. Once you reach the main shaft, jump back up to the main elevator to escape from the station.