'play on' by rick abbot, character help

hello all,

i have just been cast in our school play,
the play is called 'play on' by rick abbot, it is comedy farce about a community theatre group putting on the play 'murder most foul' by a first time writer who is letting them do it for free, but just days before opening night she keeps adding pages to the script and changes the entire plot of the play.

my character is that of billy, in the play he is stephen sellars.
i am finding it difficult to work out the type of character billy is, stephen sellars is a relatively easy character to play but im having trouble with billy.

if anybody has played this part, some sort of help would be much apreciated. or if you are familiar with the play.

thanks in advance
david