Wolfenstein Youngblood has many different collectibles to find and collect such as Readables, Concept Art, 3D Glasses and more! If you manage to collect them all you will net several different trophies / achievements such as 3-D, Audiophile, Librarian and Hacker.
There are several to find all of which are scattered all throughout the game. Warning though in order for the Floppy Disks to count you need to decode it at a Floppy Terminal.
Below is a guide of where to find each collectible found within Chapter 3 – Catacombs