Beautiful start to a novel! "The valley looked lovely these days"--implying there were days it didn't look so lovely. We are drawn in.
Great setting. The two scouts sent out, and only one returns, but the people decide to build their settlement under a volcano anyway. The image you provide is a haunting landscape. The sharp rocks concealing hungry predators - wow!

One suggestion: I find this to be a little comma-heavy, or clause-laden, but I know, I know, in the fantasy genre, this is the norm.

If this is chapter one of a novel, I might say your opening pages are a bit heavy on the exposition, vs the author putting us in the POV (Point of View) of a protagonist and showing stuff as it happens. This reads like a history, and that's fine, and that's how The Illiad was done, but years of fiction workshops hammered into me this idea that we need action and conflict up front. Noah Lukeman's book "The First Five Pages" is often recommended. Yes, I bought it. I read it. But I keep thinking how I still like Jane Austen and other 19th-C authors who'd be railroaded in today's fiction workshops.

“There are hundreds of good books that explain how to write. Noah Lukeman’s The First Five Pages is different. Lukeman’s approach is methodical and practical, beginning with presentation and working through common blunders with modifiers, style, dialogue, point of view, characters, tone, focus and pacing….. Let’s hope for a sequel….. The First Five Pages is an excellent resource that writers should keep on their shelves. The chapters on repairing dialogue (including “informative,” “commonplace,” “melodramatic” and “hard to follow”) are especially fine, full of insights that I haven’t seen elsewhere….And even though his task is to explain all the things that writers do wrong, it’s clear that Lukeman genuinely likes us and understands what makes us keep writing, even in the face of repeated rejection.”
–Downtownwriters.com

You have a great setting and you're off to a great start. Keep going!! later, come back to those opening pages and see if you want to implement any of the popular advice from agents and editors and those often-soul-crushing workshoppers. E.g., to pick just one paragrah,

Young adventurers went on long journeys in an increasingly wider area. These journeys brought them nothing for a long time and fewer and fewer young men were inclined to participate in these dangerous expeditions. The question arose whether it was not a waste of young lives. Those that did not come back could have added much value to building the village and the working land.

Not a thing wrong with the prose, the punctuation, any of it. Workshoppers will squawk, "you repeat the word young three times in one paragraph." I've been trained to notice such things, but most readers won't trip over trivial nits.
Just, maybe, a bigger sense of #immediacy might emerge with some minor revisions.
I would never presume to alter your author's VOICE - or impose another author's style. "Word economy" and "lean prose" are still in vogue. Workshoppers might suggest something like this:

Young adventurers risked their lives on long journeys, going farther and wider yet finding nothing. Those that (who) did not come back could have added much value to building the village and the working land. Fewer and fewer young men were motivated to continue these dangerous expeditions. Were they not a waste of young lives?

But KEEP WRITING and worry later about tightening the word count and all that.
This is epic stuff. :)