I'm looking for the best way to create a damaged and burnt apartment interior wall after an alien shootout. I'm thinking to shoot the actor in front of a green screen that way when the shooting is done and he looks toward the once "intact" wall, I can substitute a destroyed one showing the carnage from the alien weaponry.
(I'm new to this so bear with me). So I'm thinking to take a photo of my set wall, then add the damage in photoshop, then put it on my green screen. Then add some other fx with AE giving it some motion and life.
Is this how I should be thinking to go about it? Or is there another way?
You are thinking in the right way but it depends on the kind of camera move you have in your footage. It there is some camera movement then you should know how to motion track the footage. If it is still then not a problem but if there is camera movement then you have to go through many other procedures other then chroma keying.
The right direction, but I would recommend some research first. Videocopilot has some great tutorials and a great set of pre masked elements for stuff like this that you can combine to get the look you're after- Action Essentials.