What I want to know is when we use capo does the scale of the tuned string shift?
What does it mean for example if I put capo on the second fret?
If no capo is used then the scale is "E B G D A E".
So, what happens to the tuning when I use capo?
The capo is designed to transpose everything by the same amount. So, with an open tuning of E A D G B E, putting the capo on the second fret will make the new 'open' strings F# B E A C# F#. Putting on 3rd fret will make it G C F Bb Eb G and so on. It's really simple and basic, like fretting a particular string in the same place.
However - you use the term scale, and I wonder what you think that actually means. In music a scale is a set of notes, in order, played ascending or descending. Using a capo has no direct effect on scales.