Kill 1 Nurse.
At the beginning of the game you will find your first weapon, the knife, pull it out of the mirror and you will encounter your first enemy: the nurse.
The nurse has great potential to rip you apart, their movements are very spastic, which makes their attacks difficult to dodge correctly, especially if there is a group of them.
The best way to deal with them is either at long range with your guns, or with melee, but their is a little trick.
When encountering nurses turn OFF your flashlight and walk don't run, after a little while the nurses will simply freeze in place. At this point as long as you keep your flashlight off and don't run or bump anything they will simply stand there. You can take this opportunity to just leave the area or use any melee weapon. Do a charged X attack to knock them down, then go to town on them while they are down.