This is the easiest Silent Hill costume to make. If you can't make this accurate you might consider that cosplay may not be the right hobby for you. XD

Henry has dark brown hair, not too short. His hair seems very thick and fluffy so a wig might not be a bad idea if your natural hair looks different than his and you're not willing to get it colored and styled the same way. Don't forget the five o'clock shadow!

Against common believe Henry does not wear a white, but a very light dove-blue, buttoned shirt with two pockets on the chest. The bottom hemline has a slit on each side and he wears the shirt not completely buttoned up at the top so you can see the white t-shirt he is wearing underneath it.

He wears a normal pair of men's boot cut jeans and black, laced shoes, probably leather.

That's about it, for props I'd recommend a golf club or the rusty axe since those are the more memorable weapons from The Room.
If you want to be really funny carry Eileen's purple purse with you.