If your account is an administrator account, then you can make yourself a site manager of any site that you’re a member of.
Note: Users who aren’t an Alfresco administrator don’t have this
option. They need to request a role change from an existing site manager.
In a site click the gear button, then Become Site Manager.
You are now a manager of the site. You’ll see that you have additional options available when you click the gear button.