How do you build an online community from scratch without existing audience?

Hi. I’ve recently joined a startup as a community manager. It’s been about three months now, and I currently manage their social media. My role is mostly around spotting trends, noticing viral posts, and turning those insights into content. Our primary channel is LinkedIn, and we repurpose the same content for X and Reddit.

Now my manager wants me to build a customer community from scratch.

This is where I’m stuck.

We don’t have a strong social media audience yet. The business does have a few customers, but convincing them to join a community feels like an uphill task. Right now, I’m struggling to understand what the right first steps look like in this direction.

Most advice I come across talks about leveraging an existing audience. But we don’t really have one. Even if we launch a new group or a dedicated community space, I keep asking myself. Why would anyone join it?

I’m trying to decide where to start.

Do I focus on publishing genuinely helpful content first and hope people discover it over time? Or is it better to manually invite a small group of existing customers and start conversations with them? Should the community be public from day one, or does it make sense to keep it small and private initially?

Honestly, I feel stuck and a bit lost.

If you were in my shoes, how would you approach building a community from scratch?

What would you prioritize in the first few weeks?

Sorry for the long post. I just needed to put this out there and would really appreciate some guidance.