Ask HN: Just launched. Zero users. No clue how to market. Resource suggestions?

I'm individually messaging folks on reddit who've indicated interest, or who are very likely to be interested. I'm following and interacting with relevant industry folks on Twitter. I'm going to begin reaching out to bloggers soon.

But I'm not getting anywhere and I feel clueless. To the point it feels more productive just going back to developing app features for my non-existent user-base.

Any courses, books, or resources with practical, idiot-level advice?

It's a consumer-focused app related to books.