Something that trips up Paratext users – if you want to specify a different font for the Greek or Hebrew in the source language text, there is a special way to do this. When the source language text is the active window, go to View > Font and Color Settings, specify the field (you probably want your Greek font and Hebrew font for both word and lemma) and specify the desired font.
Changing the font in Project > Language settings does not work in Paratext 7 and is now impossible to change in 8. But changing the View > Font and Color settings does work in both 7 and 8.