I am needing to make trace words in the air. I understand that I can use a text layer and apply the stroke effect however how do i sync it to the movement of the finger? Do I need to use a null object and if so how do i parent it to the stroke effect cause its path is ultimately what I want the finger to follow. thanks in advanced!
Depending on the shot, you can use motion tracking to follow the finger and then use a solution found here to trace the path.
However, unless the finger perfectly draws the text, it will likely look messy. Your best bet is to probably manually follow the finger to draw a path and then keyframe the stroke completion accordingly.