We've got your back. With the Tough-O-Meter, you'll know whether to bring extra layers or Swiss army knives as you summit the literary mountain. (10 = Toughest)
(2) Sea Level
"The Gift of the Magi" is a blissfully simple, short story. It's written as if an wise old man were telling you the story orally, and so it feels much more casual than your average piece of literary writing. At moments the vocabulary is sophisticated (as you might gather from the phrase "imputation of parsimony" in the first paragraph), and perhaps a bit dated. There are also a couple Biblical references that you might not get. Other than that, this story is not difficult to read or understand.