In this walkthrough, you'll encounter not just zombies but bosses that will take more than bullets to knock them down. If you enounter quick time events, it will be in italic. If it's a boss fight, it will be in bold. This well help lower the confusion. Most of all, if there is danger, there would be a warning attached to it.
Pay attention to your surroundings as there is a few more to look out for. Look out for boxes that you can break to get more ammo. And look out for hidden sigmas that would reveal hidden files for the Special Features.
Last of all, if you're starting the game, you'll go straight to the "Prologue" which is the next page. Go through that and you'll be able to start in any chapter with any character partaking in the story with exception to Ada's Chapters.