Spaces can be built as Private or Network-wide and can be upgraded to an Open Space to include Guest and Restricted accounts. For sensitive conversations, you may create a Private Space and only invite members that need access to that conversation or content.
Consider creating a Space for just your content. This space can be for drafts or starting an Idea that needs further development before you are comfortable sharing the Idea to the entire network.
As long as you are a Space manager or owner, you can change the access level of a Space at any time. Hovering your mouse over the icon to the left of a Space's title will give you information on its current access level.