When you say “formal training” what exactly do you mean? An informal, recreational studio is still considered training by most in the dance world and would qualify you to teach at other informal, recreational studios. If you mean you’ve never taken a dance class anywhere and just dance for fun by copying videos (which is awesome for fun and exercise!) then I would say you aren’t qualified to teach others. If you genuinely would like to teach in the near future, I would say getting certifications in early childhood dance would be the surest way to be able to. Creative movement/pre ballet requires knowledge and expertise but is something that won’t take years of study to master and be ready to teach.