The dialogue is way too chatty and on-the-nose. There are also formatting issues. Many of the scenes drag on much longer than necessary. Sam and Michael's dialogue starting pp. 18-20 is deadly. You want to keep dialogue short and tight. Say no more than is needed. Most of that dialogue is redundant and could be summed up more briefly.
Some of the dialogue is on-the-nose. You waste words when you tell the audience what they can see.
Code:
OFFICER CAMERON
That be him sir. Apparently he made
a very frantic call to 9-1-1 at about
three a.m., talking about how "they"
were coming for him and apparently
others who were here in the house
with him. The dispatcher couldn’t find
out much about what was going on
because he was so hysterical. Then
the call went dead, we showed up
here - but with the exception of Mr.
Roberts’s girlfriend whom we found in
the upstairs bedroom closet, there’s
not a trace of Mr. Roberts or his
other family members or anyone else
- anywhere.
Sheriff Collins slowly walks into the living room.
OFFICER CAMERON
There’s just blood all over the house.
It looks like a murder massacre
happened here. The entire house
looks ransacked. Furniture thrown
around everywhere, televisions
busted. It looks like a horrible fight
may have went down here between
the family members and the "they"
of which Mr. Roberts was referring to.
The audience sees the condition. They heard the 911 call. Cameron can be brief.
Code:
OFFICER CAMERON
No trace of Mr. Roberts. At first just
this blood trail until we found his
girlfriend upstairs in the bedroom
closet.
Sheriff Collins slowly walks into the living room taking in the
wreckage--toss furniture, broken lamps, overturned television.
OFFICER CAMERON
Looks like they put up a helluva fight
with whoever Mr. Roberts was reporting.
The biggest challenge with dialogue is to not be too chatty. Pages 7-11 is slow repetitive droning about the girls outside. This could be tightened up to two pages instead of five. So yes, there are pacing issues that will make this drag.
Another issue is that you use dense paragraphs rather than break out shots. So your film is actually longer than you expect. In a properly formatted script, one page is roughly one minute of screen time. So a 60 page script runs 60 minutes.
Code:
A police car pulls into the driveway of a house. Several
other police cars are around the house. Officers, paramedics
and detectives are walking all around the house. A crime
scene photographer is snapping photos of the outside of the
house. The house is surrounded in yellow, police tape. Out
of a police car comes SHERIFF COLLINS (57), a tall, slender,
white male with short, gray hair. Sheriff Collins walks past
several officers, paramedics and detectives and walks into
the house.
Breaking this out into shots:
Code:
The house is surrounded in yellow, police tape. Several other
police cars are around the house. Officers, paramedics and
detectives walk around the house. A crime scene photographer
snaps photos of the outside of the house.
A police car pulls into the driveway of a house.
SHERIFF COLLINS (57), a tall, slender, white male with short,
gray hair exits the car, walks past them and enters the house.
Reading through it, if money is an issue, this script will be an even bigger financial challenge. The special FX will be daunting. Honestly, you want to start with a script of no more than 30 pages. A properly formatted script takes about 2-3 hrs per page to shoot. That's 75 hrs just to shoot. Now most projects you shoot 12 hrs per day, so that about 6 shoot days. And for most hobbyists, that's three weekends to shoot a 30 page short. With a proper script, one page is about one screen minute. So you're looking at three weekends to shoot a half hour short. Add in makeup and special effects and your shot schedule gets stretched out further.
Based on your script, I'm guessing it would be more like 80 pages if properly formatted. Given this is your first film, I'd wager it will be more like 4 hrs/page (which includes makeup), so 320 shoot hours. With a 12 hr shoot day, that 27 shoot days or 14 weekends (about 3.5 months). I'd venture this is a $10K investment minimum.
Maybe, you can tape some of your "youtube clips" and use that as a campaign teaser on Kickstarter to raise money to shoot the film. I'm not trying to discourage but urging you to evaluate what is possible. Keep it simple when you make your first film. Good luck.