Document editor looks like this:
First row contains template name and save button. You can use it instead of selecting file - save.
Menu contains useful tools for managing various items. Some of them have shortcuts with icons.
In left upper corner, there are shortcuts for page setup, editor and task preview (shows, how current project actually looks like).
Under menu ribbon, there are editor buttons for formatting text.
In left pane, there are buttons for new items. Read overview about possible components here.
Center has document editor/preview area, obviously.
In right pane, you can change properties of currently selected object.