Does the motor crank when you try to start it? if it does not then you have a problem with your starter or battery. If it does then your problem could be fuel related turn the key to on but dont crank the engine ...listen out the door towards the back of the car do you here a buzz or humm if not you have a fuel pump issue. if you hear the hum then you have an ignition problem and if this is the problem start by checking for an engine code. You need 3 things to start your car 1 fuel 2 air and 3spark your missing one so investigate and get back to us we can help with more info from you