I know I heard that song intro.
It might just be a familiar chord progression. I can’t tell by ear but if you post up the chords someone smarter than me might know some songs that use it for the intro. (To me, the way it’s being played feels more like a bridge, but I think that’s just a personal taste thing.)
The index finger is at the second fret. Second and third string. First is I play the first string 5th fret and than the first string on the 4th fret. A major chord and than Em.
Maybe it is a bridge. But I heard that before
Those are the notes A, C# and A. That is not an A major chord as it’s missing the 5th scale degree (E).
Those are the notes A, C# and D#. That’s not an Em chord.
Do you mean the A and D strings? Those are strings 5 and 4, respectively, as the strings are counted from thinnest to thickest.
In that case (i.e. “first” string referring to the low E), the notes are (1) A, B and E which is an Esus4 (has A instead of G#) and (2) G#, B and E which is an E major chord.
I know. I play at the beginning the notes A and D on the second fret and A First string 5ed fret. Than A,D and G sharp. Than the A chord and after that Em chord
doesn’t sound familiar. Doesn’t sound like blatant plagiarsm to me 
It vaguely reminded me of the into of “de zwemmer” by Dutch singer Boudewijn De Groot.
REMINDED ME OF, not “sounds like”…
This is it but from the differnt musician.