Suggest Starting Lines For A Debate?

Why I am standing here?
Who forced me to speak?
Surely there will be a bombastic issue,
Surely there will be a terrorist issue,
and that issue is ...(your topic)

Start with introducing yourself and your debate ..

Depends what you're debating. Some pretty typical ones that you can't go wrong on are:
 

Ladies and gentlemen, I am here to oppose/propose the unthoughtout, terrible motion/fair minded motion that this house believes/this house would ... (whatever the motion is)