OPENING PDF PROBLEMS ON IPAD PRO 11 inch

So i just got my new iPad today for school , during the afternoon everything was fine and i was able to see pdf files.. but like 7 hours later i am not able to see NOOOOO PDFs on google classroom and this is a problem because i have assignments due and because of this virus going around i only have online school so i really need someone’s help out there and i barely have apps on this iPad the only apps i have is google hangouts, google classroom, google docs, gmail, google drive, pupil path, Netflix, khan academy, and google meet i have no photos or files in this tablet. And the funny part is, is that whenever i make a document on google docs and i attach it to google classroom when i press the document it says that the file is not found and i 100% knowing i done a document so idk what to do PLEASEEE help