Why won’t my Tucson start?

Hello, it sounds like you may have more than one concern here. A hard time cranking the engine and just getting a click noise sounds like an electrical concern, start by testing your battery to ensure it is fully charged and able to handle a load. Then test to ensure all cables and connections are secure and free of corrosion. Is there a concern with the transmission shift lever sensor that detects what gear you are in -- maybe not thinking you are in Park or Neutral to crank the engine? Testing is needed. As far as running, sounds like an engine performance issue that will need to have troubleshooting performed.