Won't start only clicks

Possibly Battery, check if it's holding charge, Maybe a loose connection. I'm not a mechanic however this resolved a clicking for me.

this issue is either connection issue of cables or solenoid is a problem and depends if you bought the starter from a reliable auto parts store.

This has happened to me a couple times because I don't drive my car every day. This could happen if you go on a long vacation and your car just sits, especially in the cold. If you plug your car's battery into a car battery charger, you may be pleasantly surprised. It may take 8 hours, more or less. These chargers can be picked up at any auto parts store for under $30. Beats a new battery or being persuaded to get a new starter. I hope this helps!