How do I break into concert photography?

Do you do concert or live music photography? How did you get into it? What are some things you wish you knew then that you know now?

For context:

I’m still new, just started shooting on mirrorless this year (Sony a7III) and I know I have a long way to go.

I currently haunt local drag and burlesque shows and have managed to make a very small name for myself in some of the circles of performers in these scenes. None of my work is ever paid, I sometimes get invited and offered free admission in exchange for photographing the show. I don’t mind, I like this, it’s part of what makes me excited when it comes to photography.

My problem is idk what’s next. What I’ve done is fun, and many of these groups I would continue to photograph their shows for free simply because I enjoy it. However, idk how to get to the next level, which for me feels like live music photography.

A friend invited to photograph his show at a music venue and I was one of four photographers there with photo passes, it was so cool, but I was the only one who didn’t work for some media group.

I’ve emailed these groups with my portfolio and an introduction of interest in working with them, but never heard back.

Even if I never do this full time, I’d love the break into freelance work of this level