PLAY THE TUTORIAL!
Yes, the opening area does teach you how to play the game, but it’s a rough crash-course that you may not pay much attention to because things are always trying to separate your body from your soul. After completing what is essentially the game’s prologue, you’ll have the opportunity to choose your starting preferences. On the final screen of this process you can either confirm or you can press Triangle and experience the tutorial.
The tutorial teaches you the different stances, how to succeed in combat, how to manage your health and Ki, and other useful tips that will keep you alive a lot longer than if you went in blind. It’s not very long, so you don’t have to worry about missing out on all the action, and it gives a good feel of the mechanics in a nice, safe environment. This should definitely be one of the first things you do.
