The personal workspace menu gives you a direct access to your collections and personal documents. Personal spaces can only be accessed by their owner, by default. You can of course share the access to your personal space with other users.
Content creation and edition, as well as management, works the same way in personal space as in workspaces.
To create personal documents, follow the same steps as for any other documents and it will be displayed in your personal space.
A My Favorites folder lets you access to your favorites and manage them. Read the Favorites documentation page for more information.
A My Collections folder lets you access to the collections you have access to and the ones you created. Read the Collections documentation page for more information.