First of all, I agree with getting a riding instructor - they'll teach you how to ride properly and safely if you get a good one!
As said before, you don't really kick, just squeeze. You should be using equal pressure with both legs, not just one: just place your outside leg (if you're on the right rein, that's your left leg) behind the girth slightly. Ask for a slight inside (on the right rein, to the right) bend from the horse; many riders (and horses!) find it easier to canter from sitting trot whilst leaving a corner, as this helps to horse and rider achieve the correct leg.
To check you're on the correct leg, you can glance down quickly at your hores's shoulders: the outside shoulder should move forwards before the inside one, and that works on both reins, that's an easy way to do it!
Good luck! :)