Microsoft no longer supports installation or update support of its Office applications on macOS Monterey. They support the current and two previous releases of macOS.
Apple's Pages, Numbers, and Keynote that are presently in the Mac App Store require macOS Sequoia v15.6 or later for installation, so that eliminates your option for current versions of these applications.
If you ever installed these Apple applications from the Mac App Store since Fall 2013 using your Apple ID, you can get the last compatible versions available (v13.1) for macOS Monterey. You would do so by launching the Mac App Store, signing in with that same previous Apple ID; pressing cmd+0 (zero) to open the Purchases panel, and choosing to download/install Pages and Numbers. Do not click Cancel for any dialog during that process.
If not the previous paragraph, there is no means to get versions of Pages and Numbers for Monterey now. You could use Pages and Numbers for iCloud, but in any event, these are not clones of Microsoft applications and will convert (translate) Word and Excel files into Apple's Pages and Numbers document formats. The original Microsoft documents are not changed, nor editable. Apple does not guarantee the accuracy of these document conversions.
At this point, that leaves you looking for an MS Office clone: 1) the free LibreOffice Suite and its supporting documentation, or 2) the single, or subscription purchase of SoftMaker's Office 2024 or their forthcoming Office 2026. The latter has human support and the user interface looks like it came right from Microsoft. Unlike Microsoft's support policy, either of these choices will run on macOS Catalina through macOS Tahoe and later.