In fact, there are so many things in early childhood education. Self-study is also possible, but theoretical things can be learned, but practical things are not just learned. You also need experience and can provide you with learning. A garden of opportunity. The certificate is a must. Many kindergartens now require the certificate and your demonstration class. In terms of subject selection, you can study one type, but it will have limitations on your future development. You can start with the subjects you are better at, such as Montessori, Orff, or parent-child, etc. Being a good early education teacher is not a matter of a few months, but a long-term accumulation. Work hard! Good luck!