As for bullying, there are two types: unintentional (put that in air quotes. This is when someone realizes they might be pushing the envelope but don’t have malicious intention and are unaware of how serious it is. I myself was guilty of this once and I deeply regret it to this day) and intentional (which is malicious and done with the intent to cause harm). The first one is easier to solve. Better communication, empathy, and development of social skills is the best way to go. The second one is more difficult. At worse it stems from sociopathy and sadism, which are very difficult to fix, if possible to fix at all. Honestly IDK how to solve this one.