NISSAN 300ZX ENGINE NOT RUNNING

I Had An Accident In My 300zx And The Air Bag Came Out But No Part Of The Engine Was Harmed, But The Car Doesnt Wanna Start Anymore, It...

When I First Start Driving The Car Won't Shift Into Third Or Fouth I'm Not Sure What Gear It's In When I Take Off But I Drive For Awhile...

So, This Is My First Time Asking For Help On This Site So I Will Say As Much As I Know So I Can Get A Better Answer On My Issues. :( So...