We won't bother with layers yet. The floppy disk symbol is unimportant. Before you start drawing you should rename the file. Keep a copy of you file on a floppy disk. Note that unlike most programs there is no need repeatedly to save in MicroStation.
Saving is automatic.
The Help Menu is useful but may not be active on all machines due to lack of space. The rectangle shown above on the drawing sheet is actually a drawing. It is a 15 m x 21 m rectangle to give you some idea of scale . It is roughly the edge of an A4 sheet. Draw inside this area.