That uncial script is hard to read for somebody used to Classical Greek
(The late) Bruce Metzger wrote a book that looks helpful: Manuscripts of the Greek Bible, an Introduction to Paleography. It's too pricey for me, though.
My Greek skills are quite deteriorated, but I didn't find the pictured scrap hard to work through.
I hope the Vatical Library takes very good care of that treasure.
When I was in practice, I could read Homeric Greek well enough to read it out loud with feeling and translate it as I went along. I did a class for my daughter's (then) 7th grade class on Cool Greek Stuff, including readings from Homer and discussions of various translations (we also had some neat artifacts - copies - of swords and the Mask of Agamemnon to keep the boys entertained, as well as baklava) . . . she's now a college freshman . . . it's been awhile!