Hey there - if you selected 'private' during the community creation flow, everything in that community will be private. However, there will still exist the concept of "public" and "private" channels, however those scopes are still constrained by the community settings. For example, a private community with a public general channel means everyone who has access to the community can see those conversations. But if you have a private channel in a private community, only a subset of authorized community members will be able to see those threads.