Before creating a group, think about a platform. To begin with, it is better to choose one social network and try to develop a community in it. Analyze where your audience is concentrated, what kind of content you would like to create for them (videos, longreads, powerful stories, etc.), and what promotional opportunities you would like to use.
Content is the reason to subscribe to your group. Make sure your posts are useful to your audience, publish content regularly and actively answer questions