to start with you need to check the fuel pressure in the fuel rail, this needs to be done electronically as the pressures involved are high, the target pressure for the engine to start is 300 bar.
If you're unable to check the fuel pressure then try a small amount of "easy start" or similar in the intake, if the engine starts on this then this would confirm a fuel problem, bear in mind if you remove a fuel pipe the system will need bleeding.
If it is a fuel problem make sure the low pressure pipes are good and not drawing air in.
If the engine won't fire on "easy start" then you need to compression test the engine as it may be the timing chain has jumped due to a tensioner failure.
Also make sure the immobiliser LED goes out as it should and that the instrument cluster is displaying the mileage, if the immobiliser LED is flashing fast then the immobiliser system has a fault although usually the engine doesn't crank, if the cluster is showing dashes instead of the mileage then there is an issue with the engine management control module.
Start with these points, let me know if I can assist further or if you have more questions regarding this and I'll reply as soon as I'm able to.