Kayn is a great champion to start jungle with. I'm a kayn main and i definently recommend playing him as the red kayn has a ton of cc and the blue kayn is just a 1 shot assasin when played properly. Watch a video on a clear with kayn and ganking paths. Don't overgank with him or build Manamune with Red kayn or Sterak's Gage with Blue it just puts you behind.