I'm writing a story what I made up and I want to know how good it is from the view of peoples who know something bit more about
40k universe. once I finish the story I want to try to get it published as a novel but firstly I need some advises.

Here is little extract from chapter 4 which is called "Battle on life or death" so hope you enjoy it and give me some advises so I can make it better
btw English is my second language and I was learning it just only for 3 years now

so sorry for the mistakes
Sergeant Darito already gave the orders and splited up with the group A. Group A was just a decoy so the group B leaded by the sergeant Darito can attack them from the west.After some time group B could hear some shooting and they saw a flash of green light a little further from the camp and that meaned they can attack so the sergeant Darito gave his group a signal to move against the Orks. They all moved a bit fast so they can still aim with their boltguns. Sergeant Darito had just a chainsword and boltpistol it wasn’t the best combination but in his hands this combination was extremely dangerous. When they saw first three orks going after them they started to shoot some of the bullets missed but those what hit ripped one orks hand off and the other two killed. One of those two had big hole in his massive chest and the other one has his head blown up so some of the Space Marines were covered in a orkish green blood but there was still one ork alive and he was charging sergeant Darito with his choppaz in his still remaining musly hand. He was shouting "Waaaaaaagh" as he was running. Sergeant Darito just shot him with his boltpistol straight in his heart and then chopped his head off with his chainsword. Ork's green blood was on nearly every Space Marine near to the sergeant Darito. They all started to nearly run ahead the Orks and when they sawed them they started to shoot at them. Orks started to spread around and trying to chop some space marines but instead of that they all being killed. The bullets were flying through the air and Orks. The noise from the boltguns and assultcanons was incredibly loud but no one cared, they all have been trained for that. You could smell the smell of freshly fired bullets and the smell of blood in the air. You could see how everybody was fighting, fireing theirs weapons or just trying to protect some of theirs battle-brothers. Thay all have been fighting side by side with their battle-brother. There was this small group of four terminators they have been standing back to back to each other and trying to protect each other from the Orks. They have been fireing theirs stormbolters and if the ork get a little bit closer they smashed him with their powerfist or cut down with their chainfist. They have been fighting even if they known they are doomed but they knew if they die that they will die in the Emperor's name.In the time one of the orks was about to smash one of the terminator's head into two peaces with his choppaz sergeant Darito shooted the ork in his head. The blood covered whole terminators mask but it was already covered in blood from some more orks what he smashed in his powerfist "Watch your self or you will die very soon." shouted sergant Darito at him "Yes sir and thank you sir." answered back the terminator to the sergeant Darito. The orks kept coming fro the underground of the camp.It was like never ending wave of orks. When sergeant Darito chopped one of the ork's head off something hard hitted him in his head. He felt down on the ground facing the ground. He thought he was dead. Every Space Marine what was around him tried to get to him so they can bring his body back to the main base. They all made a big circle around sergeant Darito. One of the terminators from group A came to him and looked at him. In that time sergeant Darito opened his eyes and tried to recognise where is he and what was he doing there. After that he touched the back of his head and he felt nothing but he was feeling like a dreadnought stepped on his head. He standet up with the terminator's help then he picked up his chainsword and boltpistol. He was looking around and then he saw one lonely space marine trying to save him self from the big horde of orks which he was surrounded by. He had boltgun in one hand and a little sword in his other hand. He was firing into the ork horde and then when some ork get closer he just killed him with his sword but he didn't saw the ork what was behind him. The ork chopped his arm with the sword in it and after that he chopped his other arm and after he chopped his other arm and he just sliced his head into two pieces. The red blood was all over the ork.