Why wont the car start but it make a click sound when you turn the key?

A clicking sound when trying to start a car is almost always a low battery. The solinoid which engages with the ring gear isn't getting enough voltage to move it's gear. This causes a fairly rapid and regular clicking sound something like 6 or so per second. Attach a battery charger for 15 minutes or so or get someone to give you a jump. Then consider what the problem with the battery may be before you get stranded.