Reading, writing, and mathematics are the basics. Then you build onto that with History, Languages, Arts, Sciences and Literature. To be a good teacher, you will need to also learn child psychology, public speaking, and logic. There are so many courses that apply, and it is a lifelong effort to become the best you can be. Many of the courses offered in college are geared specifically for becoming a teacher. You can contact a guidance counselor at the college of your choice and they will be pleased to send you some information. Something else to look into is What are the requirements of the school where you want to teach? Each state has slightly different requirements and may require you to pass a state exam in addition to holding a degree or certification. In other countries the requirements may be very different. Also, it will be different depending on whether it is a publicly funded school or a private academy.
