Winning a Ranked match wont come easy. It takes knowledge of your character and knowledge against your opponent. The more you play the easier wins will come because you will learn the tendencies of online players. People are creatures of habit and you will notice that people repeat the same things over and over again online.
You only need to win once to earn this achievement.
For Kan-Ra the best thing to learn quickly is to always have sand on the ground. With a sand trap out you can using the explosion move to teleport to your sand trap from anywhere on screen. This is your best way to escape from people being in your face. Once you have Shadow meter using it to put out the Shadow insects is a great use of meter because it controls where your opponent can go. Learn the timing of all his long range normals.