What would be the worst scenario that could happen? People say "hope for the best and prepare for the worst", so what's the worst?

A meteor could crash down on your school... or more realistically, you could fight with your friends, get a bad grade, experience bullying, or have some awkward moments like walking into the wrong classroom. The truth is that there's no one worst-case scenario for middle school, and you're going to have unforeseen experiences and a mix of good and bad days, just like you did in elementary school. It's okay to be nervous and want to be prepared, but middle school isn't one single event where you can rehearse every situation beforehand; it's several years where you're growing up, learning how to interact with others, and figuring how to deal with conflict and more responsibility. You're not going to get it perfect the first try - nobody does. Instead of trying to prepare for the worst, focus on taking things day by day and being willing to ask for help when you need it.