Adjust the header margin in your template.
Set the margin top/bottom in the properties of the Template itself. This margin applies to everything except the header and footer. If you want to give the header/footer margin you can set this in the properties of the header/footer itself.
For example if you set the Template margin-top to ‘2’ and the header margin to ‘0’ the header stays at te top of the page, but the other content wil be placed lower on the page