Both of these achievements are found fairly early on in the game when you are wandering the streets of Troy.

Look for this building that says "Cafe" on it (it is in the section right before the area with the Bar).


Once you are inside this building, make your way around the counter and find this door on the left


Enter the door and then head up a bit by the sink and take a look at the trashcan like so:


you should now unlock:


Head back out to the main area of the cafe and this time head over to the right, behind the bar, and find this door:


Enter the door and you should see a medkit on the desk just to the right:


You should now unlock
Definitely not Ketchup

Home Alone, Writing Talent, Going Up?, Stocked Up, Running Wild, Wet Feet, Fresh Air, Darkness, Going in Circles, and Together Again? are all story related and cannot be missed.

Mercy Killings, Whispers, Fighting the Urge, and Statues are all based on killing enemies. Mercy Killings require you to kill the basic enemy type 10 times (these are the grey skeleton enemies you first encounter), while the rest just you need to kill the enemy once. However, my achievement for "Fighting the Urge" didn't pop until I encountered the enemy for the second time.

It can be easy to get lost at some points (especially with the lighting), just be sure to use your flashlight, save often and follow the red arrows.