In the File menu hit ‘New From Template’ (Ctrl+Shift+N).
Select folder ‘…/QCAD/libraries/templates/imperial’ where ‘…’ is your installation folder.
Select template ‘ANSI A Landscape’ in inch.
Hit ‘Create new Drawing’ in the dialog.
Unfortunately, this standard example template is not using Block Attributes.
There may be numerous other examples on the QCAD site or in the forum.
Anything in the public domain is free to use unless otherwise noticed.