Discipline multiplied by age group is the map of this market. "Karate for kids", "BJJ for adults", "kickboxing for teenagers" are separate searches with separate competition, and every combination that gets its own page brings enrolments that otherwise never arrive.
September carries the whole year. Searching starts in mid-August when the children's week is being planned, and the page has to exist before the summer — published in October it will only be ready for the following season.
Self-defence is a field of its own with a different motivation behind it. Someone searching for it wants neither competition nor a belt, just to feel safe walking home — and they find almost nothing that speaks to them on a typical club site.
Gradings are worth writing about too. A parent comparing clubs wants to know how often they happen, what they cost and what's expected, and the club that explains it looks organised in a way no photograph achieves.