When getting your sign from the catcher, keep the following pitching tips in mind:
Your first step back will be with your glove side foot. You can step straight back behind the rubber or you can step to the side. Step a comfortable distance away from the rubber that allows you to pivot that foot and begin turning the hips to line the body up to the target. Generally this step is anywhere from 8-18 inches long, depending on the height of the pitcher.
The approach helps the pitcher position himself to pivot the pitching side foot in front, touching the front of the rubber. So it's important that the approach allow him to pivot that foot while maintaining body control.
Don't be too precious with this first step of the windup because as you will see, you must learn to develop a good rhythm and tempo that fits your style of pitching. Go too fast and you can lose body control. Go too slow and you will become too mechanical and lose pitching velocity not maximizing your athleticism.
Your rhythm must fit your personal athletic ability. Compare it to a sprinter. If a sprinter gets off of the blocks badly then it will affect him negatively the rest of the race.
Just like every hitter seems to have a different stance, so every pitcher has his own initial approach. Remember to take a small step, 8 to 18 inches (depending on how tall a pitcher is), and either straight back, to the side or even back and to the side should be enough to position yourself correctly for the next important step in proper pitching mechanics.