A car needs three things to start: power, spark, and fuel. If it's cranking the only thing we actually know is that is has power. I could be a computer, spark, timing, or fuel issue. Guessing at the fuel pump is putting the cart in front of the horse. I would recommend paying a qualified technician to diagnose the problem. Then if you want to do the repair yourself, great! At least you will be replacing the right component. It will save you money over replacing parts you don't need by trial and error.
If it cranks but doesnt start it could be your fuel pump relay or your fuel pump could be bad.
If it just cranks and cranks and cranks then it's likely fuel pump. If it died and it won't turn over anymore, likely alternator.
Maybe your fuel pump
chances are to start with the fuel filter if that's not it try the fuel pump
check fuel pump, check coil pack.
bad fuel pump relay or fuse
I would add fuel to the tank, and then use the fuel pump relay to prime the system. Good luck. add fuel to your fuel filter and put it back on and should start. On older diesel engines dont worry about the fuel pump relay. Add clean fresh fuel to the filter and hold the pedal to the floor while cranking and it should start.(release pedal when it starts)
if its cranking but not starting most likely fuel pump
make sure you have fuel coming to your injectors, could be your fuel pump.
fuel pump could have gone bad , does it have fuel in the tank ?
clogged fuel filter or faulty fuel pump or shorting wires for pump check wires first then filter
possible fuel pump issue.