Word page is displayed incorrectly, how to change?

The notebook in the office always shows me the wrong page format. Whenever I open a new document, a page is displayed that is much too long and narrow. (see photo).

I just can't figure out why that is and how I can change it. If I set A4 in the page format is nothing at all. If I open old A4 documents, which I have created a few weeks ago but they are displayed correctly. Maybe someone can tell me what I have to do so that a new document is displayed correctly (A4) again?

Click on top left alignment. Looks like it's in landscape mode. Otherwise try to manually set the page size to a4. (420 x 594 mm)

The page format is also A4. You only have your sheet in landscape orientation. Click on Alignment on the top left and you will find your way around.

To your question, how to get a new document from this "thing":

PAGE LAYOUT - set "Orientation" to portrait,
Use "Size" to search and select the default DIN A4 (210 x 297 mm - portrait)
Now the unikumm should be gone,
Save As Select as template then .dotx or Normal Word Format .docx

Small note - the size is for DIN A 2. DIN A 4 has 210 x 297