In the course of exploring mudstack, we created a workspace for you and seeded it with some content so you wouldn't feel quite so... alone!
Now that you have a free mudstack account, you might want to create your own 'real' workspace from scratch. You could either just modify the starter workspace or create a new one.
All collaborators on a free account have access to every workspace under the account. Admin roles, view only members, and workspace specific permissions are available only on paid professional accounts.
You will also see any open invitations that have been sent to your email address here, and can choose to join those accounts before the invite expires.