Answer:
If I could change anything in the world, I would change the government system. This is because the government rules more minor subjects like school, transportation, economics, and more. By changing the government system, these subjects will also slowly start to get better for all citizens. Some of the problems many people are facing are trouble in school, money bills, etc. These problems can come to a stop only when the governors decide to fix them. A realistic way we can fix this problem is by kicking some governors (who didn't help the nation for the better) and giving much more reliable and wiser people the position. These kinds of people will listen to their citizens and help out as much as they can. If chaos starts happening, people should go on a peaceful protest to get what they want. This would make the world a much better place as many problems will slowly start going away.
Hope this helped :)