There are some possibilities which you will have to check in this case:--
1) First of all check the power and voltage to the battery. With meter it will show exact 12 volt if the battery is charged. If the voltage is less get the battery charged at local auto repair shop. If the battery is internally drained and not getting charged then its time to replace the battery.
2) When you crank the car do you see spark coming at the spark plug? If no then its time to check the spark plugs and coil pack. If the spark plugs are not worn out and looks new then its time to check coil pack. The spark plug gets power to spark from coil pack.
3) The other thing to check in this case is the starter solenoid of the car. If the battery is charged and you start the car then it gives power to the starter to start the car. But if starter is faulty or not connected properly then car will not start.
4) The other thing to check in this case is fuel in the car. If there is fuel in the car then check the blockages in the fuel pump if the fuel pump looks proper then check the fuel filter above the fuel pump.
5) If all the above possibilities mentioned above checked out OK/perfect then it's a electrical issue and the wiring's in the car needs to be checked. The car gets power from the battery to get started. so the wires from battery needs to be checked one by one.