downloaded Indesign (latatest verion) created a new file and want to save... says this file is dammeged..done nothing yet. It's a white page

You download InDesign via the Creative Cloud app. Having downloaded it you open InDesign and select File > New and then you enter dimensions such as the page size, bleed, number of pages etc. You then name and save the document and you can subsequently add text and images to the page(s).

What’s your operating system version? Can you post a screenshot of the error? Does it happen to this file only or any other file as well? Where do you attempt to save the file (your local drive, cloud storage, network volume etc?)