A great and free place to start is Facebook groups – find and join parents and Mums groups and offer the safety training and there might be some hair stylist groups too?
Work your networks! Get them to share posts from your Facebook page.
You can boost posts offering trainings to people with the the job titles hair stylists and interested in hairdressing etc too. It’s cost effective – only costs about $10 to reach 1000 people so you if you have some spare dollars give that go.
Eye catching imagery or even a vide of you cutting a kids hair and very clear copy in the first sentence (eg/ Learn how to cut childrens hair!”) is the best way to be seen and understood in a busy newsfeed.