Chopping out rhythms for Chopin's Fantasie Impromptu?

[chopinlover01]

So, it's 3 against 4, at least at the beginning. Any advice for slicing out the rhythms on this? (Starting to get a basic feel for it now, so when I start learning it in about 9 months, it'll be easier)
Also, I've heard it's easy except for the rhythm. Is that true?