What to do to recover deleted files
Look at your backups.
++ Adding to the discussion
Have you saved the PDF file to Adobe Document Cloud? If yes, please login to Document Cloud here - https://documentcloud.adobe.com/link/home/ and check for your file under the Documents Tab and see if that helps. If you haven't saved the file or deleted the file directly from the storage on your device or Document Cloud, there isn't much that we can do to recover the lost file.