A bad clutch can lead to more damage. If the clutch is not releasing all the way, then gears can be grinding and cause internal damage to the transmission. A clutch release bearing could have failed and causing the noise. If this doesn't get replaced, eventually it will cause damage to the clutch pressure plate. Sometimes it is a simple adjustment that is needed. Most cars these days don't use a clutch cable. They use hydraulic system to transfer the clutch action and there is no adjustment. If it is a click sound coming from pedal, then it could be that the return spring is catching on something.
I recommend having a mechanic test drive our car and give you an opinion. It could save you from causing more damage.
Thanks mate! Very informative!