Quickbooks for the Mac has an export function. In the File menu, you can choose Export and specify "to Quickbooks for Windows." Because you will be using this exported file for Windows, do not use special characters in the filename. Also, within the Quickbooks files on the Mac, try to find and change special characters inside various fields and make sure your transaction memo fields are not overly long (under a few dozen characters). By special characters, I mean things like !, @, $, ^ etc. I believe that Windows might not recognize some of those characters in filenames or inside the Quickbooks file fields.
When you export when on the Mac, a Windows file will be created. I can't do this right now to test, but I believe the file extension will be .QBB or something similar. I believe technically Windows looks at this file like a "backup" type file. On the Windows version of Quickbooks, choose File and Open/Restore and Restore a backup (QBB), and then select the QBB file from the Mac.
I would do this now, long before you really need it, with one or two test files to make sure the series of steps does work and produce a valid and correct Windows version of the Mac original file.
https://quickbooks.intuit.com/learn-support/en-us/help-article/data-security/convert-quickbooks-mac-file-quickbooks-windows/L8uZd4Zry_US_en_US