I was excited to see that the costumes for part of it were designed by Sartori (of Berluti).
I am a real ballet virgin. Never had an interest to go. But I am also a history and culture buff and thought I would grab the opportunity to go there. This could turn me on to ballet.
Ballet, modern or classical, is among the more sublime forms of artistic expression and experience. I sincerely hope you enjoy it. I can't imagine a place that would give you a better first time experience.
That does, indeed, make it easy. You should wear whatever makes you most comfortable.
That seems unlikely, but I'l take your word for it. But so what?
Well, the first ballet I ever attended was in Garnier. I was married for year or so, my wife had a business trip to Paris, and I tagged along. She managed to get tickets for "Parsifal - Episodes et écho" by John Neumeier - this was a true spectacle by Hambourg Ballet. I then realized one thing, people with good old classical education can easily enjoy ballet, and pick all the clues and references given out by music, movement, scene and costume. It was fascinating that I was able to understand the "story" with only vaguely knowing who Parsifal was.
I don't think it's entirely necessary to have a certain type of education in order to enjoy ballet, or any form of dance, really. It can be enough to appreciate the artistry and skill of the dancers.