Is this good writing?

I'm 13, and I want too be an author. This is just a random extract from my book, but does it sound professional and it my writing any good?

Martin Hersav looked at the mounds of dead, rotting bodies piled around him and on top of him. He breathed in deeply through his mouth, trying not to gag as the stench floated up to him.

He tried to establish what exactly had happened to him. All he remembered was-

He couldn’t remember anything.

He tried to recall something. He searched were he knew his childhood memories should be, but there wasn’t anything there. There wasn’t anything anywhere. He had no history of his life.

He moaned in despair and twitched slightly, aware of dead, rancid bodies above him. A belts buckle dug into his sternum and he shifted a bit more, and suddenly felt a jolt as he tumbled onto the ground, more and more dead bodies rolling on him. A large group of crows suddenly flew into the air, cawing loudly. Martin struggled, lifting the limp dead over him, and pushing them away until he was finally free and able to breathe.

Martin slowly stood and looked around him. What he saw looked like a small castle. There were burnt buildings and piles of dead bodies. The stone walls were crumbling in places and a horse skittered around the ruined gate, trying to get out of the castle it was entrapped in.

Gore-crows pecked at the mounds, and Martin was aware that he stood on a battlefield, though were was still a mystery to him.

Martin slowly rose from a crouch, and his head suddenly began to spin and his legs wobbled. After steadying himself on a spear buried in one of his companions chests.

Companion? Why did he think that? He closed his eyes and concentrated. What was he doing here? Had he been involved in the fighting?

He looked down at himself and saw dented armour and blood soaked under clothes. His left leg was badly bruised from the thigh down, and his right eye was tightly closed.

Martin looked and felt like a mess, but at least he was still alive. Unlike the other men in the kings army.

Kings Army? Yes. He thought back, straining his mind and Martin was suddenly overwhelmed by images.

A scribe reading a decree about the Kingdom wanting soldiers, a burly man presenting him with a standard sword and wooden buckler, hacking away at wooden dummies, firing an arrow, laughing around a tavern with men he would fight with later, being fitted in armour, saying goodbye to his young children and family.

Then, suddenly the images stopped as a voice rang out over the keep.

“-nothing worth looting here, Jon. We shouldn’t have come here, it gives me the creeps!”

Another voice, probably Jon’s, spoke. The voice was squeaky and high-pitched, though had an air of cunning and malice.

“Hush, child. We raid the battlefield so we don’t have to slit the men’s throat ourselves. And this is a well fortified keep. They are bound to have some riches inside.”

The other man replied, but Martin wasn’t listening. All he knew was that there had been a battle here, but for what reason he still didn’t know.

He looked up, slowly peeking at the men, until he was satisfied they had entered the keep and began to search around him for a weapon. He didn’t fancy fighting the burly young man, but the older one of the pair had a look about him that spoke of murder and assassination. He didn’t want to have to fight him.

Anyway, he wouldn’t fight them if he didn’t have too. All he wanted to do was get out of this keep and then-

And then what? He began to wonder to himself. What could he do from there?

He needed to find a way to somewhere safe and get a wise-woman to see to him, that he knew, but what else was he to do. He vaguely remembered the faintest memory of his daughter and wife, but where they were right now he didn’t no.

No, he needed to get back to his commanders. He thought about this for a second and came the the conclusion that he was a soldier in the King’s Army, and that he needed to report to his overlord.

First, though, he needed to get out of the keep and away from the rotting flesh and mutilated bodies.

He stepped onto the body beside him and with a twist pulled the spear out of the body, wiping the flesh on the spearhead on the dead man’s tunic.

Then he slowly hobbled over to the gate, glancing back every now and then to make sure the two looters were still inside the keep. He also made sure not to walk to close to the panicking horse nearby, which seemed to have an arrow buried in its side. It also had saddlebags strapped over it’s back and Martin hoped there was some food and water in them, as well as some wine to wash his wounds.

He slowly moved towards the horse, which looked at him warily. “Good boy, good boy,” Martin said, trying to coax it into coming closer. He rubbed his fingers together and the horse thought he had food, but when it realised he didn’t it leaped back with a loud neigh.