Unknown serial number cannot contact Apple support

HI,

so I bought a second hand 2008 MacBook a couple of years ago and yesterday I dropped it. The base took the main impact but the screen is

i do not have the original packaging, or receipt or invoice. I am desperately wanting to speak to some one at Apple support, but cannot access this service without my serial number!! How else can I either contact Apple support without my serial number? Or how else can I access my serial number?

please don't suggest visiting the apple shop that's is over a 4 hour drive away.