Flash player isn't supported on iOS devices. Does the site that you studying on have a non-flash version of it, or do they have their own app in your country's App Store ? Or does the site have info about using their site on an iOS device ?
For Firefox Mozilla have an iOS version of their browser : https://geo.itunes.apple.com/app/firefox-web-browser/id989804926?mt=8
For Office Microsoft have apps (Excel, Word, PowerPoint, Outlook) in the App Store