If you are only trying to create a different header for the first page, Word make things a lot easier. Just check the "Different First Page" option on the toolbar while editing any header.

It’s common to display a different header or footer on the first or last page of a document. You can use the built-in Different First Page option to display a different header on the first page.

However, each time I create a new header, it changes my previous headers. What’s the solution to creating different headers? A. As a default in Word, all subsequent headers and footers link to the ...

If you want to skip numbering the first page in Word online, click the "Insert" tab on the ribbon menu and then click "Header & Footer." Click "Options," then click "Different First Page." ...

If for whatever reason you want different text on the first page, click the check box labeled “Different first page header/footer” on the lower left of the header box.