Hi secora47267766 ,
In Acrobat Reader mobile app. there is no option to download the PDF file from document cloud on your device.
However you can do this online via web browser.
Open this link https://cloud.acrobat.com/recent on iPad in the web browser, Sign In using your Adobe ID & under the Document Cloud tab you will see all the uploaded file, select it & download it on your device.
Later you will be able to see the downloaded file in Acrobat Reader mobile app. under Local tab.