That's something that business majors have to take a couple courses in. It's all a bunch of theoretical busywork. To ignore marketing makes it harder to find students and reduces income sharply. Marketing is figuring out the kind of students you want and how to reach them to let them know you're available. Most people think that advertising and marketing are the same thing, but this is not the case.
Advertising is only one aspect of marketing.
Let us discuss each one separately. Parents for children, adults for themselves. Other private music teachers. Dance, martial arts, Scouts, and sports. And then there are religious instruction, volunteer work, higher education, overtime work, lethargy, family resistance, and so on.