I have a John Deere X304 and when I turn the key to start it it clicks but does not turn engine over. In the recent past when I go to start it I have had to turn the key 2 to 4 times before the starter turns the engine over. It runs fine after starting.

It is possible your battery lacks power and the click you hear is the solinoid in the starter, Begin by cleaning the battery terminals and check that the battery is recharging properly