In terms of overall arcs,
Johnny - I believe this was the highlight of the series and the one I'm most looking forward to in the 2nd season. Johnny is a jerk, to put it lightly, due to his poor home life as a child. His step father used money instead of parenting to solve problems and as a result Johnny doesn't know how to cope in the real world. He drowns his own problems in alcohol. His relationship with his own son has been damaged, possibly beyond repair. All he wanted to do was win that karate tournament and beat Daniel in the 80s, and his life would have been better, or so he thought. When he finally gets that win in the present, it doesn't feel as good as the thought, because of the way it was earned. That inner turmoil of finding that balance is something that he has yet to achieve and that journey is the one I'm most interested in seeing.
Daniel - While it was mostly fun watching his story unfold and waxing nostalgic, the story I'm most interested in is his role as sensei to Robby. Also, back to Johnny, I can't imagine how hard it must have felt for him to watch his son being close with and taught by his enemy, Daniel. Johnny reveals to Miguel that John Kreese was a father figure in his life so seeing Daniel in that role will hopefully add to Johnny's journey to improve himself. I did love seeing Daniel and Johnny rock out together to REO Speedwagon in the penultimate episode. If things had been different in the 80s, they might have been friends. And I still stand by the line in KK1 when Johnny says, "You're all right, LaRusso." validating the audience that he has earned the respect of his enemies by standing up for himself. Obviously, with John Kreese choking out Johnny and destroying his trophy and then Johnny leaving the Cobra Kai had a profound impact on his life but we didn't get that story until now.
Miguel / Robby / Samantha - These three were the highlight of the children as the rest were pretty much "comic" relief. It was great seeing Miguel rise from loser to winner and get that confidence they needed in their life, similar to Daniel in KK1. It's sad to see Miguel take a turn towards the "dark", but as we know, there's no such thing as a bad student - just a bad teacher - and IMO Johnny isn't bad, just misguided for the time being. I'm glad Robby found a teacher/father figure in Daniel which prevented him from turning to a life of crime. Sam is wise beyond her years, and based on the Season 2 trailer, will add herself back into the narrative of the karate world which is better than the snooty rich mean girl world.
Honorable mentions: Aisha and Hawk. I liked their mini arcs of gaining confidence. Hopefully they don't lose themselves like Miguel has started to.
Small nitpicks aside with some of the corny dialogue, plot holes, and characters like Anthony & Amanda LaRusso, Kyler, Moon & Yasmine, and Daniel's cousins, I think we have a pretty good foundation to the Cobra Kai series and I look forward to what we get in Season 2.
