unless your instructor hasn't prepared you at all, you won't bust. i know how i felt when i took the checkride considering it is the first one, but you will be ok. learn everything about your airplane (mine was a C-172), VFR weather stuff, WHERE to find specific regulations, as in if the exaimer asks "you notice the nose strut on your airplane is low, can you fix it yourself? you could say "well sir, that sounds like it would be in part 43 of the regulations for maintenence". be careful not to dig yourself a hole when you answer his questions, because if the hole gets big enough it will be your grave.
the flight part shouldn't be anything more than a vfr x-c by pilotage and dead reckoning, and then divert usually after about your second checkpoint. then airwork, then you do your landings, and then you PASS!
make sure you sleep good the night before, eat breakfast, and bring the cash for the examiner