How do you get clients online?

I own a music company where I provide tutors for those who want to learn a musical instrument online. This is my second actual business, the first one didn't fail but it took so much of my time and it wasn't fulfilling for me. I see my competitors using Facebook ads, but FB ads are quite expensive for me (for now). I also can't do lead generation, I'd have to pay for a business email (can't for now). I actually want this to flourish but I'm super new to business and my last one didn't succeed. Any tips? :>