You get what you give. What’s the best way to learn but to teach. Starting anywhere. Looking for a mentor? Become one. There are many who would benefit from what you know already. Concepts you think you understand get complicated the moment you try to explain them to somebody who has no clue. It forces you to clarify and understand it on a baser level to be able to simply convey that idea to somebody. The need of accountability that arises within the relationship between you and somebody you teach is a boost towards self-discipline.
Teaching doesn’t have to be sterile or academic. In fact, especially when working with the youths, that burst creativity, the academic approach is likely to kill their enthusiasm by applying one-fits-all methodology to teaching. Working with youths is one of the most rewarding experiences and seeing their creative spirit rejuvenates that same energy in us. Surely there’s a youth club where you live. If not you can consider joining one of many projects that support financially under-privileged communities all over the developing world.