Developing and efficient stroke is a process.
Firstly the best technique to start with is the side kick.
Now I will walk you through this practice.
1. Lye on side in the water, one arm in front just below the surface, ear on shoulder and other arm still by the side.
2. Kick in freestyle action side ways for approx. 10m
3. Alternate sides changing at every 10m.
4. Knees should pass each other each kick.