When you begin printing, your extruder starts to click, and continues to click for the first few minutes
This happens because the filament is unable to be pushed through the nozzle.
1. Check the temperature of your nozzle and make sure it is hot enough to melt the filament. For PLA that would be 185C.
2. Level your bed. If your bed is too high the filament cannot extrude. By re-leveling the bed, and lowering it a notch, your issue should be resolved.