These links go to the Confluence Documentation website:
The Space Admin controls are found in the Space Tools menu at the bottom of the left sidebar in a space.
If you're the owner of a space or you've been given Space Admin permissions by the owner, you'll see these menu options to control user access and permissions, change the look and feel of the space, and modify various other settings
Check out the
User Access and Permissions
Grant access and permissions to users on an individual basis
All about wiki accounts, space types, and permission types