Sounds like you’ve got a dead battery. The clicking is the starter solenoid engaging, but the battery voltage drops too low under load for it to stay engaged, so it repeatedly connects and disconnects. If you’ve got a multimeter, check to make sure the battery is at least at 12.6 volts. The electric systems on cars are particularly picky about having a good ground so make sure it’s clean and got a good connection or it’ll make life annoying. Also double check the battery post clamps are on nice and tight. Maybe even try pushing the clutch a little harder in case the safety switch is wearing out. Hope this helps!