Most likely, you're not remembering where you saved the file. InDesign can corrupt a file, but it's almost impossible to "lose" a file.
Choose File > Open Recent to look for recent files.
Or, use the search feature on your operating system to search for it.
Since you are using the Creative Cloud Files folder and file syncing please check the Archive at https://assets.adobe.com/files?filter=archive. When items are deleted or removed from the Creative Cloud Files folder they go into the Archive. From there you can Restore or Permanently Delete items.