Usually when your car does not start, it means dead battery. But even if after you had tried to jump start the car, and the engine does not "crank" (ie. no crank sound), it means the battery is still fine.
One possible solution is to shift your transmission to neutral (if you have automatic transmission), and try to start the engine from "N". This is because even if you had the car in "P" park mode, the transmission might still get stuck at "D", so the vehicle is not allowing you to start.
By shifting the transmission around and finally to "N" neutral, you might be able to unstuck the transmission and get your car started.