I'm wanting to change a book called Being and Nothingness by Paul Satre from pdf to something a phone app called UB reader will recognise, I am using calibre-ebook.com, but don't know which format to use, so far it's nothing but a mess. Or should I copy the entire book to Windows notepad, and then convert it from that? Please help, thank you.
If you are referring to this website: http://www.mobisystems.com/android/ub-reader/ for the UB reader app you mention in your question; then they state on their homepage that the:
Universal Book Reader is a stylish and user-friendly eBook reading app for Android.
UB Reader provides a comfortable reading experience for Android smartphones and tablets, allowing you to read EPUB and PDF files - DRM-protected and otherwise. An integrated file browser allows you to quickly add any eBook stored on your device, over email, or through the Feedbooks.com online store.
So if you have the content in an EPUB or PDF format you should be good.
From a professional production standpoint Calibre is not recommended, there are a lot of validation and poor coding standards used by Calibre.
Therefore converting it in InDesign or possibly professionally having the epub converted is advised.
InDesign should have no issues creating an ePub correctly. Be sure to export the fonts correctly though to avoid font licensing issues.