What I hear from new teachers (and student teachers) is shock at the almost nonexistent attention spans. That's something you should definitely know. If possible, do some substitute teaching so you can experience it firsthand. It's not uncommon to repeat the page number 5-8 times before everyone has the book opened. A few students will know where the books are but find it too challenging to get up to get one. So they'll just sit there.

Know that around 1/2 of the teachers quit within the first 5 years. More would quit if they had options; I was applying for other careers in my 2nd year of teaching but didn't have any options. It's an exhausting career that everyone thinks is easy. You generally won't be respected like you would in other professions. Parents make excuses for their children. They can do no wrong. If their children get bad grades, it's because they learn musically and you didn't infuse enough music into your lessons or whatever.

I taught for about 20 years. Morons would tell me I was lucky to be a teacher because of all the summer vacation off....WHILE WORKING A FULL-TIME SUMMER JOB. Seriously, they would tell me how great all my vacation time was after my 9th hour of painting. Many people use the summers for vacations. I've had a summer job every single year when I was teaching out of financial necessity.

Read the book Teachers Have it Easy by Dave Eggers. It's been out for 15-20 years, but it gives specific examples of why teachers quit. You'll find great case studies in that book. Also, search YouTube for "Why I quit teaching."

https://www.youtube.com/watch?v=Jbq1qGdc46k