car wont start at all?

just got the car from a family member. it a ford fiesta 1.2 on a y reg. the problem is i put the key in to start it up but there was nothing my radio wont work either. nyhows i tryed again and still nothing so i got it towed back home but whilst i was getting towed my petrol gauge speed dile and temp gauge was jumping back and fourth i thougt it could be my blackbox? but not sure any clues to what this could be many thanks