Windows 11, Office 2021, MS Word

I want to print some 4 x 6 postcards and am having great difficulties getting the Word format right. When I decrease the margins, Word increases them cutting off my text. Go to View -> Views, and select Print Layout. Then when I press ctl-P, it changes the format and cuts off some of the text.

I am old and not good with the finer details of Word. Please make the instructions simple.

Or maybe will someone create a template, an example document, that I can use? Get the text to within ½ inch of all the sides. Maybe write the text as instructions on how to format it.
Thank you for your time.

Edit: I changed my profile to Windows 11 and Office 2021 but the change did not show up in this post.