Just for fun, I touched it up a little. If these were my characters this is how they would speak because it's closer to my own speech and thus sounds more natural to me. Maybe it won't work for the characters you've created but most of the changes are minor. I also cut the stage directions a little. It went from 653 words to 606 and I think it flows a little easier now.
Nick: It’s fucking cold up here.
Adam: It’s the rain.
Nick: You put all your stuff in trash bags?
Adam: Why would I do that?
Nick: That was some heavy rain. It probably went right through your pack-cover.
Adam: Really? Shit.
Adam digs inside his pack. He removes a stove, mountain house, and a ziplocked copy of The Fellowship of the Ring and sets them on the rock. He exposes the top of his sleeping bag, it is damp.
Adam: Shit. Shit. Shit. How am I gonna sleep in this?
Nick: It’s not goose down is it?
Adam: Synthetic.
Nick: It’ll still keep you warm.
Adam: You think?
Nick: It should. It won't be a very pleasant evening though.
Adam sits on the rock and rubs his temples.
Nick: (Re: book) You’re still carting this book around Frodo?
Adam: Yeah.
Nick: I saw the movies. I read it in highschool…I didn’t like it very much either time.
Adam: Really, if you think about it, The Lord of the Rings was about a thru-hike.
Nick: What?
Adam: It’s three books of Frodo walking to a mountain. Aragorn, Gandalf and the others fight a war. Frodo, he sees some action but mostly it’s just he and Sam walking.
Nick: Yeah…I remember most of the book being like that. “Frodo took a step. Then Frodo took another step. Then Frodo looked at a blade of grass, and then Frodo took another step.”
Adam: “And then a huge exciting fight scene happened—Somewhere else.”
Nick: “And Frodo took another step.”
They laugh. A pause.
Nick: Where do you suppose Frodo resupplied?
Adam: What?
Nick: Well, if it’s basically a thru-hike, then they must've carried pretty much everything on their backs, right? I mean it’s not like there’s a postal service for Bilbo to send him mail-drops.
Adam: Hmm…Well in the shire they were staying with relatives and stealing food. Then they stayed with Tom Bombadil, and then onto Bree for a townstop. They stayed at the inn…
Nick: And met Vigo Mortensen.
Adam: I guess Strider was hunting and foraging for them in the wilderness.
Nick: Like the kid who showed up at Neel’s Gap with a bow and thought he was going to hunt deer the whole way to Maine? Good luck carrying a deer carcass around out here.
Adam: Then they went to Rivendell.
Nick: And stayed with Agent Smith.
Adam: So they resupplied there, and then they tried to get to Rohan, but couldn’t get over the mountain.
Nick: Pussies.
Adam: So they went to Moria for like a week. They probably intended to resupply with Gimli’s cousin but the dwarves were all dead.
Nick: Because of that fire-guy.
Adam: The Balrog.
Nick: Gesundheit.
Adam: So still no food…Man they’ve gotta be starving.
Nick: I can’t stand missing even one of my three snack times, and they’re going a week without food?
Adam: And then they meet up with more Elves…and they get the lembas bread.
Nick: What's lembas bread?
Adam: A plot device; magic elf-bread. One bite fills the stomach of a grown man.
Nick: Sounds like Little Debbies.
Adam: So they’re eating off that, until Gollum gets rid of it and they…
Nick: What?
Adam: Dude…then they’re in Mordor. No lembas bread, no resupply. Frodo and Sam don’t eat for like, a month or something.
Nick: That's outrageous.
Adam: I guess Tolkien wasn’t a hiker.
Nick: Obviously not.
Adam: Maybe they lived off their fat?
Nick: Those books are fucking bullshit.
Adam: They’re about Elves and Goblins and Hobbits.
Nick: Point taken.
I'm not sure if the format for plays is identical to that of movies but if it is check out
The Hollywood Standard by Christopher Riley. I'm following it for a movie script I'm trying to write.