I like to be in the company of people who are smarter &/or more adept in an area than me. It is stimulating. I do not, however, like to teach, talk or present (preach?) beyond my capabilities. I've made the mistake many times for sure but we are to learn from mistakes. The nice thing about getting older is being who you truly are and not trying to be someone you're not. Age gets you seated on the rock of integrity.
Back to you teaching what you know. I do not follow the policies and politics of yoga in America. However, I hear occasional talk of national certification, but there are no requirements to teach at this time. The technology of yoga is vast. Goodness gracious, you do not need to know all of it in order to teach. Start where you are. If you have the desire to lead asana, breath, meditation, concentration or any other teaching from the yoga tradition, I encourage you to follow the impulse.
Find a venue that works for you: a little corner somewhere, indoors or outdoors, with a group, an individual or within an established yoga studio or school. Or you can write, or make audio and video recordings. Find the schedule that works for you too: full-time, several times per week, once per month.
However and whatever you teach is like touching a bit of eternity. The teachings have been handed down for thousands of years. Step into being part of the lineage if inspired to do so. Again, if you listen carefully to your intuition and teach what you really know, you will be teaching responsibly.