Many of us already know why racism is bad. But:
White people are the minority since Asians and Black people are more in number.
Back to the subject, there are people that get offended for good reasons, since they are victims of racism, but some of them become extremely annoying, because they get offended and overreact over non-existent racism acts. For example, most of the black people get offended when they hear the N word (nigga), but that is just an appellative, which is not even addressed only to black people. It also means black, so they offend themselves, underestimating their skin color, thinking that was addressed to them for offensive purposes. It is just like that classmate that induces himself in a stupid, worthless depression stage then he calls life a mess. Now, don’t get me wrong, I find black people working in retail, for example, more friendly than white ones. It is in their genes. But usually, they are also the loud ones. That is not necessarily a bad thing since that makes them better at speaking and acting, but if you try to stop a black person from holding their point (interrupt them) they will get offended in a serious way. Many things like this also happen to Asians.
Stereotyping is also something that is not supposed to offend anyone, but it does. Why? Because people hate when others assume that they are something or do something they do not. I was told I wear the same clothes every day. For some reason, that offended me, even if I did not wear the same clothes.
A simple life hack
Are you going on a holiday and you are afraid to embarrass yourself? Take this advice: Carefully read for about 10 minutes about what problems that country has or even search for what the people of that country hate.
Example: In England you can end up in a fight or argument if you joke about drinking (their policy is harsh) or talk with a superior tone to emigrants (it's easy to spot one, they just stand out). Let's say they laugh loudly in a canteen. Instead of saying: "Shut up!" or "Keep it quiet", say:"Ummmm... Excuse me... Can you please keep your voices a little bit lower?" But you have to say this as you are a waiter. Do not be too bossy but neither too scared, so they will somehow feel bad if they will keep being noisy.