You would be better of to count through the previous phrase and emplply the starter over the last 2 beats of the phrase. Thge starter step could also be a shifting of weight as someone else mentiond. ( you shift the lady to your Right side to prepare to move the left foot) I am assuming you are a leader by the way. (since counting is such a big deal for you)

If you are doing American or night club cha cha, the foot does move to the left side on 1. By the way , you should always double up you counting. for example Rumba has 8 distinct beats not 4.
You can count 2& 3& 4& 1(&)(step on the numbers and brush your feet on the &'s)