I recommend that you translate your way through 2 Cor. 4 first. This will give you a feel for both vocabulary and grammar.
Then come back and start engaging with these files below. This will give you a review of the verses you just translated, as well as giving you a feel for trying to read through a longer passage all at once.
Before reading the version below at the 900 word level, flip through the the 20 words that are used more than 900 times in the New Testament.
When you decide to try the 450 word-level version of 2 Cor. 4, precede it by reviewing the stack of 21 cards that are used 450 times or more in the NT.
While this flashcard-review strategy works well with the Gospel of John and 1 John, it doesn't work quite as well with Paul's writings. He tends to use a broader vocabulary than John does...including words that are not used very frequently in the NT.
Still, linking your review of flashcards with the reader's version of this passage you have downloaded to your desktop computer or your phone is about the best strategy available to us for improving your general fluency in Greek.