start outside and look for the external wall box - 6" square ish usually on wall facing road or pavement - brown or grey usually - follow any cables that come from it and go inside - if there are non look inside opposite external box as they may just have drilled through wall - as said it may just be a cable rather than an internal wall box
if you find a cable you need one of these to attach the cable that came with the quick start kit
okay was able to attach photo.. this is the NTL box, it's the same as my bt one where I had my broadband connected to but had an adaptor which my cable went into. Where as VM cable is slightly bigger and doesn't fit.
ok - so thats also a phone box and not what you want need - maybe the cable for BB has been removed - worth following the wires from that box outside - it should go to an external box see if there is a thicker coax cable - if there is follow that if it goes inside
if all that is fruitless then you need a tech - try this
pre-installation and delivery team on 0800 052 1734