It's a translation of Tolkien's "Ainulindalë" in The Silmarillion (p.3) into Old English. I was bored, and a full explanation would be too complicated. 😛
It means:
"There was Eru, the One, who in Arda is called Ilúvatar; and he made first the Ainur, the Holy Ones, that were the offspring of his thought."
The text I made used footnotes in which the English-translations of the Elvish names were given. Eru would translated as "se Ana" in O.E.; Ilúvatar as "se Ealfæder"; and Ainur as "þa Halige."
Or is that too much?