A family of Microsoft word processing software products for creating web, email, and print documents.
Display all nonprinting characters (Command + 8) and find the Section breaks in your document. It sounds like you have a section break at the end of page 2 ... just verify ... no need to change.
With the cursor in the header for section 1 select the Different First Page options from the Header & Footers tab on the ribbon. This will allow you to adjust the header for page 1 of section 1, independently from page 2 of section 1.
For more information on Section Breaks and working with Headers and Footer see Word Help.