Thank you for reaching out!
I'm providing an answer from the perspective of a recent #college
graduate working as a #substitute
teacher so I'm not entirely sure how different it would be as a full time #teacher
but I personally love high school aged kids over K-8.
I'm not a big #math
person when it comes to anything above algebra or geometry so I would imagine high level math would be most difficult to teach. However, with higher level math you're more likely to get students who are good at math and will probably be able to catch on faster. If you're not typically a patient person or you don't like to explain the same thing 10 different ways, working with older and more advanced kids might be the best option for you. I imagine what you may consider most difficult will be completely different from what others consider most difficult. It all depends on your skill level, personality, and personal preferences!
I have been told higher ed new teachers get the "slim pickings" when it comes to what math classes they teach as other teachers who have been there longer select what they prefer and new teachers get either what's left or what's needed. If you're lucky, what you want is either unpopular with other teachers or popular with #students
. I can't remember where I heard this, but it's something to consider!
Best of luck!