I think you all know how I feel about non-piano majors jumping into teaching piano, but if you must, you HAVE to take at least one pedagogy course.
Even those of us with multiple degrees in piano (performance, ped, or both), continue with education and courses for our entire lives. We are always seeking additional knowledge and we take our profession very seriously. If you go this route, ask us questions, join groups like SLAMTA, NFMC, PTRT, or Guild, get coffee with established teachers, subscribe to Piano Inspires, and fill your brains. This is a serious profession that we work very hard at, not just a job anyone can do once they have finished a certain method book level.
If you take Lauren Lewandowsi's course, you'll have a leg up!