My 2002 saturn vue won't go into gear

Sir ,
Kindly tell us whether your engine starts up properly to idle . If yes , then your problem is with the transmission system or with the clutch plates . If the clutch plates are too empty , the gear would be almost stuck . If the car is in N-neutral , try pushing it and while moving slightly try to change the gear . Engine oil and transmission oil should be checked up regularly .
At present situation you will have to have your gear system unjammed or opened up by a professional and have your gear box replaced or checked for jammed gears which is pretty time consuming and difficult job . Else you will have to replace the clutch plates and youre ready to fly again .
Thanking you , Dixon Dominic