So.... critiquing. I'll leave aside the grammar errors for now, and focus on the writing itself.
The first problem I see is a shifting viewpoint--you want us to know what's happening, but you also want us in Larry's head. This leads you to try to hold on to a third person personal viewpoint (limited knowledge, prose that is steeped in the emotions of the moment) and a third person omniscient (unlimited knowledge, prose that presents evocative ideas as somewhat separate) at the same time. This doesn't work. Not just for you--it'll probably never work.
The second is a lack of concern. Even in 3rd om. you want to have the prose pulling the reader into an emotion that he should be feeling. In this case, it's probably disorientation and shock. As an example, you wrote: "Larry watched this for a short time, not entirely aware of whose blood it was but he was so dizzy, he didn’t really care." This is bad--I don't care about him at all. (Hint: if your characters don't care, just want to go to sleep, etc., then we might, too, unless you've provided us with a very present danger.) A better way to do this is in 3rd pers., as you can pull in question sentences stumbling together. For example: "Larry was on the ground--he was on the ground? How? Why? His head was--what was that, a dog? his head was spinning--he couldn't keep the world in focus...what was that smell? Blood? why was he on the ground?" &c. That's kind of repetitious, but the point is to break up thoughts. In 3rd om., you might consider a scene break or describing something else, because confusion is tough to do.
The third problem, related to the above, is telling instead of showing. Just remember the acronym SDT, show don't tell. Here's your telling prose: "He could only pick out a few words, “OK?” “are” “hurt” “ambulance” “doctor” “sorry”."
Here's how I'd revise it: "Faces were looking at him, crowding around him, "Sorry,"
"Ok"
"hurt"
"Doctor"
"so sorry"
His head spun further, his eyes felt like they were rolling in their sockets.
"Ambulance"
"Called it al"
"sorry"
"Ok?""
You fix these errors, then you'll have a beginning. E: To elaborate, none of these errors are inherently damning. They're rookie mistakes--once you fix 'em, you'll rarely ever make them again.