Sounds like your clutch plate is stuck to your flywheel from sitting. I have had this happen in the Challenger I had years ago. It sat for a few months and the clutch plate stuck itself fast to the flywheel.

Put the car in 4th gear, push the clutch pedal all the way to the floor, and hit the starter. It should pop it loose. You may have to rock the car a few times with the starter. Keep the clutch pedal depressed while you rock the car. Also let the car settle to a stop before you hit the starter again.

If not, put the car on jack stands and remove the inspection cover. Have someone depress the clutch pedal all the way to the foor and use a thin piece of aluminum (.030 or so) and try to slide it between the clutch and flywheel.

You may also just tap on the edge of the clutch disc lightly with a hammer and screwdriver (a broad flat one) while the clutch pedal is depressed. It should pop loose.