Make sure there is an engine in there.
Seriously if you don't know what to check I suggest that you arrange to have the vehicle inspected by your Auto Club (NRMA,RACV, RACQ, RAA etc). They can provide a pre-purchase inspection service. Will thoroughly check vehicle for ANY mechanical or electrical faults etc. Well worth the money - not too expensive. Ring them and check. Failure to do so may result in the purchase of a 'lemon' or something that may have been victim of floods, re-build, write-off etc. Your money - your choice. Good luck.