An Easy Ambush

Our story begins. We meet Brian and have a short skirmish. Note: Dialogue in Terran is italicized; dialogue in English is normal.

With sneaking footsteps, Brian followed Captain James through to forest. The squad of ten made no noise as they followed the road. They weren't actually on the road, but they made sure to keep it within sight, in case any Aliens showed up walking along it. That was what the squad's mission was, to ambush any Aliens found on the road. This was the war that Brian knew, endless ambushing an being ambushed, hiding in bushes and sneaking around. The nearest open-field battle was over a thousand miles away, and they were stuck in the middle of a forest. But they were Guerrilla soldiers, trained to fight in this kind of environment. Compared to the Aliens, the squad practically grew up in a forest. The Aliens didn't use much of any kind of training, trusting in their superior technology to carry them through the war. How wrong they were.
Humans had been fighting wars for centuries, and the Aliens have never fought a full-scale war. ***Note: Brian says "Humans" instead of "Terrans" because he considers himself Human and the enemies as Aliens. To clear up confusion, he is a Terran*** They would win with experience, deception, and sheer force of will. It would not be an easy victory, but surely, the Humans would win.
"Brian, you're spacing out," Alaska Miles said, breaking him from his thoughts. Brian looked over at her, and then checked the road about twenty meters away, still nothing there.
"How could you tell?" Brian asked her.
"Your stealth got sloppy, you started stepping on twigs and things. Please try not to kill us with your noise," she smiled.
Another voice scolded them from behind, "You lovebirds shut up right now! Your voice is what's going to kill us!"
Alaska and Brian fell silent. It was true, they did have feelings for each other, and the whole squad knew it. However, they would have to wait until the war was over. The battlefield was no place for romance. The two of them had made tentative plans for life after the war. Brian would move his family in with Alaska's.
"What's left of my family," he whispered to himself.
Both of Brian's parents had been killed in a car crash shortly before the war. His brother had been killed in action a year ago, and Brian believed it was his duty to take his place, and so Brian joined too, leaving his younger brother and sister behind. It wasn't all bad, he did get to meet Alaska during training, and now she was assigned to the same squad as him.
"Movement on the road," Captain James quietly announced. For the second time, Brian was torn from his thoughts as he concentrated on the road ahead.
Sure enough, about a dozen Aliens were walking double-file up the road, coming towards the hidden squad, looking like science-fiction stormtroopers in their armor. The Guerrilla squad crouched down and stealthily crept behind the bushes that lined the road. Brian looked over his weapons.
AK-201 rifle, check. Wristblades, Brian snapped them open from their housing on his wrist with a flick of his mind. Check.
After his brother's death, when Brian decided to go to war, he spent his inheritance on ordering wristblades like the one in the movie Predator and some neurosurgery to go with it. Within three months, Brian was able to control them like another finger on his hand.
"Snipers, target the two leading soldiers, those are the captains," the American captain ordered, "Everyone else, concentrate your fire, and make your shots count. On my signal then. Ready....."
Brian raised his rifle, an Alien already in his sights.
"OPEN FIRE!"
Two loud shots rang out as the snipers fired, both armor-piercing bullets passed straight through their target's helmets. The rest of the squad opened up with automatic fire on the confused Alien soldiers. Without their captains to tell them what to do, they were lost. Most wheeled around, trying to pinpoint the origin of the fire while others panicked. After a few seconds they returned fire with their heavy railguns.
Brian tried hard not to fire in full auto; short bursts would be much more effective against that strong armor. But still, it was discouraging to see bullets ricochet off their armor, while he had no protection of his own. A very accurate burst caught an Alien in the chest, denting his armor. Brian switched targets and fired at that same spot, his bullets breaking through and sinking into the Alien's chest. More Aliens fell as their armor became damaged and broken through repeated hits. Soon there was only one left, and then none.
"All clear!" Captain James called out, "Casualty report!"
"Lars is dead!" a soldier shouted.
"So is Hernandez!" called another.
Brian looked around him, seeing one of the snipers fallen to the ground.
"Midori's been wounded!" he cried, stepping towards her.
Midori was holding both sides of her thigh, where a railgun spear had entered and passed through. Brian could see the decimeter-long slug embedded in a large rock behind her. Damn, those railguns were powerful. He crouched down next to her to examine the wound.
"Move your hands, let me see," he told Midori in English, and reluctantly, she did. The squad usually spoke in Terran, as that was the only language they all knew. But it was more comfortable to speak in English, so Brian did whenever he could.
The railgun slug had chipped off a small piece of Midori's leg bone, there was no way she could walk without further damaging it.
"My army days are over, aren't they," Midori said through clenched teeth.
Brian tried to be optimistic for her, but to still tell the truth, "Your Guerrilla days maybe, but perhaps you can still snipe. Think about it, you are going to get to sit in a nice, cozy watchtower all day."
Midori forced a laugh, and then sighed pleasantly as Brian poured painkiller into the wound.
"Wow, I feel like a baby, being bandaged by a kid. I'm supposed to be twenty! Geez. You, and 'Laska, and Muhammad, I wonder how they let you guys in. You're too young for this s**t!
Brian said nothing as he finished tying up the bandage.
"Done!" he announced, "Don't you dare try to walk."
"Yes, sir!" she teased.
Brian walked out to the road to scavenge the corpses with the rest of the soldiers. He took water, rations, and medicine, leaving the weapons. It was not worth the reduced speed to carry a railgun; the Guerrillas were built for mobility. Besides, railguns had serious flaws. They jammed at the slightest disturbance and were a pain to reload. But the Aliens used them because they were the newest technology, it didn't matter to them how inefficient they were.
Someone stood up and gave a cry of triumph. Everyone crowded around the soldier to see what he had found. Captain James took the map from him and studied it. the squad held its breath as it waited for the news.
"It looks like troop movements," the captain said, his face unchanged, "but I don't know if they're real or not. It could be a trap. We'll end our patrol now and take them to Outpost. We'll take it to Headquarters tomorrow and have it authenticated. Let's see if we can't save some Human lives!"I
The squad cheered and the troops gathered their gear. Brian was checking his ammo when he saw Muhammad jogging towards him with the telephone.
"Brian! You have a phone call!" he called out in Terran.
It obviously couldn't wait, so Brian stopped what he was doing to take it.

Author's Note

Not really an interesting first chapter, I had to explain a lot of things, like Brian's past, his wristblades, etc. Trust me, it gets better and smoother. Yes, I chose to use metric units because they would be much easier to understand if non-American or non-English people decide to read this. I am just being considerate.
Also, do you think I should italicize dialogue that is in Terran? I'm already getting tired of stating what language they are talking in at the moment. Tell me your opinion in a review.

Reviews

[Y.]

It's picking up. You generally do have to explain bits and pieces at the beginning of stories, I feel.
Rather than have the note right in the middle of the paragraph, move it to the bottom of the page - a footnote. It's easier for the reader that way.
Since you've already explained Brian's leaning towards English, I think you should now just stick to the English in italics and Terran in normal thing.