If you're "about to enter school" (I assume college) take some classes in teaching pedagogy. Just liking guns and being a good shot doesn't automatically make you a good instructor. Critically analyze your own teachers, instructors, professors and decide what it is you think makes THEM effective. And what makes them less than effective. Emulate the good stuff, avoid the bad stuff.
Teaching, any subject, can be tremendously frustrating and tremendously rewarding at the same time. It might be quite a rude awakening, for example, to try and get across all that great stuff about stance and sight picture and whatever you may feel so great about, when there's that one goofball in the class who just won't shut up about "I don't care what anyone says, if some slug comes around me, I'll blow him away". That goofball paid for the class just like the others. You owe him your expertise just like the others. But there's a big brick wall that you'll have to get through first, in order to get that expertise to the guy.