I suppose you are referring to the different rhythms in each hand.
It depends on your current abilities and way of practicing and learning. Some will say to practice the parts separately, others to practice both at the same time. Try both and see what seems more simple for you
. It might be preferable to practice a few dozens of bars one hand at a time so to feel how the music "falls architecturally" on the keyboard. But as soon as you begin to find it doable, practice both hands together, since this is the most tricky part of the piece.
Start as slow as needed. Don't forget to use your forearm/arm weight because when you'll play everything at tempo, you'll understand you need endurance, especially when you arrive at the finale.
Another thing : practice other pieces as well (actually as we should all do with any other piece). To play this piece expressively
and not just like an agglomeration of notes or some kind of race, it takes time since one needs to keep his/her attention to the nuances and details specified througout the score.