2001 cavalier tranny or clutch problem??

For the past month or so it's been hard on occasion to get the car into gear (manual 5 speed) . After some cold weather the clutch seems to be actiing up. Now it is in the driveway. I can find the gears when the car is turned off. When I turn it on, (with the clutch depressed) it jumps into gear. The car will not start in first gear, you have to put it in neutral. Any ideas. I don't know where to start?

try bleeding the slave cylinder and check your hydrolic fluid in the clutch master cylinder.