If you practice this phrase , leave out the part of the left hand only in this bar.
Then leave out the part in the right hand of this bar.
Then try to blend these bars together. I hope you get what I mean.
If you play something as big as this. Always count while practicing !!!!
Take a deep breath before you start to play count the beat in your mind and start play. If you have a good sense of rhythm, this may not be necessary with easy pieces. But you will always stumble across pieces, that are too difficault to rely on your sense of rhythm.
Take the 2nd movement of Chopins 2nd Concerto for example. There you will see runs with 49 notes on two beats. You dont want to find a common denominator for 49 and 6

.