To enter each sheet's setting click on gear icon to manage sheets.
The gear icon may not be visible due to number of sheets, click on arrow icon to see the setting.
In this part you can create new sheet, Change name of sheets, rearrange sheets and delete a sheet.
To create a new sheet Write your sheet name in the "enter sheet title" and click on +.
To change your sheet name click on pen icon and press enter.
After all click on done to save changes.
Expand: Change how you view your list, portrait mode horizontally (this change is only displayed to you).
Rename: Change name of your list.
Move: move your lists in sheets
Archive: archive the lists you don't use anymore.