I own a 1992 gmc jimmy and I was wondering if the clutch sensor has anything to do with starting. Sometimes when I start it, it takes a few times before it starts. Am not pushing the clutch far enough down for it to engage the starter.

Yes you do have a clutch switch and it must see "the clutch pedal down" to close the starting circuit.....allowing the starter to crank the engine.
If you think it is defective you can jump it....just for testing.
Remember....jumping it will cause the vehicle to crank over when the switch is turned with out pushing the clutch...be careful!

If it turns over ever time after jumping for the next few days....you do need a new clutch safety switch.

Yes, there is a clutch switch which must be activated (closes switch) for the starter to engage. This is a safety item so the truck won't start in gear. With time it may begin to fail, this should be any easy fix. And yes from time to time you may not be pushing the clutch in far enough to actuate this switch.
I hope this may have helped,
Tom