If you prefer a pre-designed layout to jumpstart your project, several reputable sources offer free downloads: Create and update an index - Microsoft Support
How to Find and Use an Index Template in Microsoft Word An index is a critical component for long documents, books, and reports, providing readers with an alphabetical list of terms and the page numbers where they appear. While many users look for a "free download" of a standalone index template, Microsoft Word actually has a that functions better than a static template.
Where to Find Free Microsoft Word Index & Document Templates
This guide explores how to access free professional templates and, more importantly, how to use Word’s native tools to create a dynamic index that updates automatically as your document grows.