Surprisingly, Kayn is one of the most misunderstood junglers in the game. Almost everybody knows some of the strengths of the different forms, but most Kayn player are uncertain of what form they should be using. When you're first learning Kayn, it is useful to choose based on how many ranged champions the enemy team has. Blue form tends to excel into ranged matchups. Inversely, red form most often does well against teams with lots of melee characters. Remembering this will help you do well until you start learning some of the complexities of the character.

The builds you would use in any given situation are almost all standardized. All of these are covered here. There are a few niche/preference-based choices, but, overall, they don't make a huge difference in how well you'll perform. Of course, some less conventional builds do well in very specific situations, but you will be served just a well by one of these.