You first need to go to right, jump to the platform to the top left of the right and then carefully jump across the gaps. If you're referring to the jump where there is a block right above your head, you need to time the jump just right to make it past. If instead you're talking about the part where you see an object floating on a platform to the top right of the platform you're on, you need to do a well-timed leap to the right to land on a platform slightly out of view.
P.S. There is a speed upgrade and also a double jump, but you find those later on and they're not needed for the part you're stuck at. And if you're wondering, platforming does get easier later on as the focus shifts to dodging attacks.