MS Word Document Formatting

I need help formatting a MS Word document (450-page book manuscript) to fix pagination and headers. I have already designed the layout, but upon converting it to pdf to submit for publication, the headers and page numbers change, and additional pages are inserted. Specific Requirements: - Adjust section breaks and pagination throughout the document - Set headers to include chapter titles and page numbers Ideal Skills: - Proficiency in MS Word - Attention to detail in document layout - Experience with formatting for clarity and professionalism