The starting sequence is: ignition switch turns on the power to the solenoid on the starter motor which then turns on the power to the starter motor itself. If your engine does not turn at all, then there is something wrong in this part of the circuit.

If the battery is weak, then classically what you hear is repeated clicks - the solenoid is activated, the battery tries to turn the starter but cant, in doing so the battery voltage drops, so the solenoid withdraws and then the cycle is repeated every second or so.

If you just hear one click, then the likely candidate is a dirty / sticky solenoid which is activating but not going far enough to put power through to the starter motor.

Suggest you remove the starter and solenoid, and strip and clean the latter. If (as your name suggests) you can understand the arcane world of semi quavers, then a simple solenoid should be childs play.