With a high school diploma in hand, your next step should be to begin your college education at a community college or (4-year) university. Many community colleges now offer associate degrees in education, which will directly transfer to 4-year universities. When choosing a university, you should choose a school with a teacher preparation program. Not every university in WA offers a route to teacher certification for undergraduate students.
Whether you choose to attend a community college or a university, be sure to seek out opportunities to work with children and in K-12 schools. Your college or university might also have a student club for future teachers. Volunteering as a tutor to your fellow students is also a valuable experience when exploring a career in education.