Don't try to excuse yourself from not having teaching experience. Take the opposite strategy, which is largely to spend time on why you're an enthusiast/how it captured your imagination/why teaching now is a good decision/what you hope to offer.
They will know you don't have experience - don't dwell on it. Convince them of what you do have. Teaching is storytelling, acting, passion, attentiveness, empathy, logic, creativity, subject knowledge...
Don't be afraid to introduce yourself as an expert on your thing, even if you're not an expert at portraying yourself as an expert on your thing.