My Idea So Far

My idea so far is simply a teenager leaving his house and going to meet some friends on his skateboard at night. On his way to meet them he comes across a smashed up car parked in the middle of the street, he stops and walks over to the car. As he looks in the window a hooded figure comes up behind him and in the reflection of the car window you see the teenager get stabbed. The film title then comes up se3tting up the rest of the film to be an investigation as to why the boy was killed, who killed him and why was the car there; was it set up or was it meant for someone else?
I would like to work in a pair for my idea so as to share the work load and to have a range of skills whilst making the opening however I will work on my own if needs be as I already have quite a clear idea of what I want to achieve and people may not share this with me.
My film will be a drama/crime/thriller genre and will have quite a dark feel to it. This is because these types of films are ones that really appealed to me and its something I believe I can achieve to a good standard.
I plan for my film to follow a traditional narrative, starting at the beginning withy a start, middle and end. This is because I feel for my idea it would fit better for it to be in this narrative structure.
I will only use two characters in my opening; the teenager and the murderer (whose face won't be seen). This is because the teenage will be stabbed in the opening therefore I think that if I focus almost the whole of the opening on him it could get people to feel for him and get a feeling that he could be an important character and then when he gets killed it will not only be a bit of a shock and a thrill but it will draw the audience in to want to watch the rest of the film. Before any other character has even been introduced this character has died meaning the audience will feel like they deserve and really want to know why and by who. Also because I have limited access to actors it will easier to just cast two characters.
I plan to use only a couple of locations. The teenagers house which he leaves and then some very dark lit, rough, deserted streets.
I definitely don't want to do a comedy style film because I believe it will be too hard to do. it would be very difficult to make it genuinely funny and therefore I don't think it would end up looking very good.
I do not want to use dialogue because I don't think you need dialogue in an opening scene3 and because I wont be able to use proper actors any dialogue could end up making the film look very amateurish and poorly acted. Furthermore I believe having no dialogue helps to build up tension and create some mystery about what is going on.
I do plan to use a soundtrack or music in my opening to help create tension and build up suspense. I don't yet know what music I will use but I plan to use something quite dark and sinister.
I won't be breaking the fourth wall in my opening because the character who will be in it doesn't need to connect with the audience. Also fourth wall breaks are more commonly used in comedy's and documentary style films and my opening wont follow either of these styles.
No narration will be used for my opening this is because I don't need the story to explained or introduced over what's happening, I plan to try and use a bit of mystery to draw people in and narration would go against that.
I plan to use a wide range of camera shots and angles, mainly whilst the teenage character is skateboarding through the streets.