I teach young children and provide parent education.
Every day can be quite different from the next. The children arrive to the classroom and they are greeted by the teacher, our routine stays the same but the children's moods affect the plan for the day. We move along the routine in snack, meetings, outside time, small group, work, clean-up, and story time. A great day is when parents leave happy and children are safe and excited to learn.
Physical stamina, ability to adapt and work with many different types of personalities and families of various social/economic/ethnic groups. Lots of patience. Flexibility. A heart for children and compassion. Time to plan and prepare for lessons and paperwork.
Here's the first step for high school students
Spend time in a Early Childhood Education setting, classroom or in parent education.
"Why are you still just a preschool teacher. Don't you want to teach Elementary?"