A new Sequence with a new ID is created. To rename it, right-click on the new Sequence. The other commands available in this context menu are the same as in the context menu when you right-click in the time bar within the Sequence tab.
This tab displays all available Sequences as large thumbnails. Among others, it enables you, to toggle play / pause of various timelines with one click only.
To view the properties of a Sequence select it in the Project tab and look into the Sequence Inspector. It shows all settings, e.g. timecode settings and the Master Sequence opacity.