Walk to a shattered window. Get ready for a fight, there will be soldiers inside.
Get inside. Kill the soldiers and collect any goods. Then get to the control panel next to the turrets and open it by pressing the action key.
Throw in a grenade and step back.
Get outside. Be ready to kill some zombies that will stand on your way. Then move towards the direction from which you came.
You will meet Alyx on your way back. Follow her to a garage.
Get in the car and drive straight ahead. You will get to the first hidden spot with supplies. It will be a white van. To get your hands on the supplies just blow up a barrel standing there.
Get back to the car and head straight. When you get to a crossroad, turn left and drive towards a tunnel. There will be a hidden spot with rocket launcher there, but later you will get it anyway. Don't bother then.
Follow the road and mind the curves. When you get to another hidden spot, park the car and go behind a black rock.
The spot will be right behind that rock (next to a fallen tree). It will be blocked. Remove the rock, get the supplies and get back to the car.
Keep driving. You will get to a gas station. Look around, collect some goods and get back to the car.
You will get to a small village. Stop the car right next to a blue house. Get inside and collect any goods. Have a look at the ground floor rooms. You'll be needing this.
When you walk out of the house, the Combine will show up! There will be force shields around the house. Get back inside the house and stand with Alyx right next to the entrance. The first wave will strike there. Kill the soldiers.
Then get to a kitchen. The second wave will strike and there will be hunters too!
Then Alyx will decide to get the hell away as this place is a trap. Move to a room with a fireplace. There will be an exit.
Wait for Alyx to join you and then get to the place marked on the screenshot as A.
You will get to some rocks. There will be crates with supplies as well. Get them.