Angeleyes
You have a great start here and I wanted to know more, more, more!!
(and that's the mark of a good start - pulling us in, wanting more!)
As a playwright, and I think this goes as well for scriptwriters, and I'm in
the US mind you, so what I say is probably backwardass b/c of our prez, but
I digress - I won't go there.

mmm, okay, as a playwright, an list of characters and their ages, sizes,
features, relationships to each other, is always after the title page and/or
synopsis.
One exercise I learned in playwrighting class, it's called Etudes.
you can write an Etude for everything, basically, for a character, it's
their back story. Where they were born, what kind of childhood,
teen years, specific moments (if you have the time and really want
to delve into the phych of your character) everything. Write scenes
with your characters and people who are real - the president of a
big corporation, the pastor of a church. just to see how your characters
interact.
Basically, what the prof said was to let the characters tell you what and
who they are.
Sometimes it works, sometimes it doesn't.
There are tons of books about script writing and exercises to get
your script where you want it to go.
Hope I helped a little!
Can't wait to read the next scene - vampires or cute little teddy bears -
whichever, I'm on the edge of my seat!!