There are gonna be 7 achievements for just going through the game normally
-Be prepared
Finish the prologue
-Scent of Meat
Finish chapter 1
-A picture to remember
Finish chapter 2
-Whisper of another world
Finish chapter 3
-Price of a mistake
Finish chapter 4
-Last page
Finish the game
-First time doesn’t count
Die

One of the hidden achievements is gotten in chapter 2 when you get the camera. You got to take a picture of the black canvas or pictures of the people on the walls. You’ll know when you got the pic when the pic changes to a creepy version.
-Layers of meaning
Take 10 pictures of the paintings on the walls

Now there are 2 hidden achievements which are based on which choice you choose at the end. So to get the both, you just have to load the game again and choose the other choice
-Family matter
Click on the door to leave
-Recluse
Click on the book you are writing instead of leaving

There is one last hidden achievements which you have to do at the very beginning when you start chapter 1
-Common sense
Instead of going through the gate to the mansion when you get out your car, go behind you and just leave. You’ll get a little dialogue from the guy in the earpiece but just keep going.

I hope this helped you trying to get all the achievements. Let me know if I’ve missed something. If not, thank yooou for letting me help yooou