Get a comfortable grip if you're having trouble with your movement being restricted. Also, try to practice more what you lack; such as: speed, stamina, aim, streams, etc.
That's what I would say to someone who is plateauing in the game after some time, but for now just play the game while enjoying the good songs it has to offer.
You'll get a grip of this game soon enough if you're consistent. Even if you aren't, just as myself, you can get at my level in a couple years (or maybe months if you're one of those freaks of nature who is built different from any of us).