I appreciate the effort you've put in, but there are a lot of problems with this one. Right off the bat, there are formatting issues. Paragraphs starting in the wrong places, and your dialog runs too long inside the page.
Pg 1 - In your slugline: Don't use "School time". Just use "Day" instead. If the kids are in class we will assume it's during school hours.
You never properly introduce Kevin. You can't just write high school boy and then jump right into the Character's dialog. Establish the character first in CAPITAL LETTERS, with a brief description, and them move onto the dialog.
The first classroom scene is unclear. Why is the teacher talking all this crazy nonsense? Is it to see if the students are actually paying attention? If so, it doesn't work on the page.
On pg 2 - you CUT TO - EXT. Hereford - morning
Where are we? You just drop in that locale with no further reference, when a proper set up should be there. Is Hereford a town?
And then we come to the big, big problem. Do you really expect us, (or Kevin), to believe that a teacher, is she even a teacher? All you've written is -- "A lady who seems to be in charge". What does this mean. Is she in charge or not. Is she part of the film program at this school or not? Are we really to believe that this "lady", and all the students in the room have not only never seen Star Wars, heard of Star Wars, or all the Actors in it, and even if they hadn't, then could actually they believe that a kid in their school could have made this film?
Unless you segue into a moment of pure surrealism, where Kevin can't believe his eyes, entered some new weird reality, where he looks on with complete disbelief, could this premise ever work.
Keep writing and getting better,