Well to start off there is many things this could be. Some of the most common ones are actually pretty simple to fix.
The first thing i would try is taking off your battery cables and refitting them on. Sometimes corrosion, a bad cable, or a broken adjuster cause it to not have a good connection.
The Second thing i would try is charging the battery. Most modern cars have a safety built in that when the car gets to a certain Voltage/Amperage, they make it click to let you know that it needs charged.
The third thing i would try, if all that fails, is tapping your starter solenoid with a hammer. the gears inside the solenoid usually tear down after a few years of starting and get stuck. If you don't know anything about cars this could be kind of hard to do. ts usually right on the front of the engine block next to your transmission cooler, that's attached to your radiator. You should see a big cylinder with a little cylinder attached to it. The little cylinder is your solenoid.
Good Luck
it might be your starter.
there is a security chip under the colum maybe it fell out happened to me once
A clicking sound when you try to start the car is a dead battery. It may be that the alternator is not charging it properly.
Ignition switch
Replace battery cable.
either your battiery is dead or your starter is going out, probably the battiery though
Low Battery
Maybe flat battery?
Some cars have a separate starter solenoid. If this is the case, I am willing to bet that is the issue. If not, check the wires. You have a bad connection or a fried wire.
If clicking while trying to start then might be a bad starter. If clicking while running, then might be valve/lifter noise.
Does the engine turn over and then make the clicking noise while trying to start, or does it not do anything but make the clicking noise when you turn the key. If its not turning over at all then it might be a battery problem, Try cleaning the battery terminals, and/or charge the battery, Could also be the starter solenoid, but start with the battery first.
clicking noise when trying to sart engine usually indicates a flat battery.if the battery is not the problem ,the starter motor needs repair.