Hello I would liek to help you with this.
this Sounds like a problem with the Neutral safty interlock switch.
This Switch is what prevents you from starting the car in any gear accept P or N
it might be that the Swicth is out of adjust ment or has failed.
Try this Make sure your e-brake is on and working and you foot is on the brake. Try and start the car while movingthe shifter. if you cna get it to start then the safty Switch is out of ajust ment. If not then it most likely has failed.