So you just asked for an answer to a question that is basically endless but I will try to cover as much as possible. Better than just writing points about what I learnt randomly, I would say what I learnt from each character one-by-one
Naruto taught me that life can be tough, and people will ridicule us and we may be at our lowest but we should always keep a smile on our face, stand up and fight back. He taught me to set a goal and work hard accordingly for it without thinking whether fate allows it or not because I create my own fate.
Sasuke taught me that no matter how born-genius one is, we shouldn’t let our friends slip away and we can only realize how important friends and family are, once we lose all of them
Sakura and Eno taught me that we may not be as talented as our peers but that shouldn’t demotivate us but work harder and harder to reach their level. Competition in life helps us become better
Kakashi taught me that pain is an important part of our lives and sacrifice has to be made which will define us but we have to handle them always with a smile
Hinata taught me the value of love and innocence and also that our family background and traditions don't define us, It who we are and want to be that matters
Kiba and Akamaru taught me the value of friendship and how we can rely on our true friends when times are tough
Shino taught me how silence is a trait and it doesn't even closely show how much powerful you are from the inside
Shikamaru taught me how we need to be calm when we are facing problems because we can always find a way out
Choji taught me that snacks are tasty
Asuma taught me that we need to fight endlessly maybe till death but never let anyone hurt the ones we care about
Rock Lee has taught me many things but in short, he is the embodiment of sheer determination and burning will. We may not be born- talented but our hard work defines us too.
Neji was bound by his family traditions and customs but he never backed off when the duty called and put himself forward to be a better person
Gaara taught me that no matter how dark our origin can be, the light always shines upon us and we should value virtues of friendship and be a better man
Obito and Itachi shows the value of friendship and love and how it can change our ethics
Nagato shows how pain can change us and if we let it, it can even define us
Hashirama and Madara defines the circle of honest innocent friendship and no matter how hard life tries to separate us but the fights don't define what we feel for each other
