ok. 6th string is the E string
then first fret is F then 2nd is either f# or Gb right?

and say i wanna play the F#, how to position my fingers? if i wannaa play the Gb chord(im not sure if there is) how to play? i dont really know what are the notes for though..but i assume is to play chords

In the musical notations, F# = Gb. So If you want to play Gb, it's the same as playing F#.

If you're just playing a single note, then just press a finger down on that 2nd fret.

But to play the F# chord, just position your hand to play the F chord (barring the first fret and etc), then shift all fingers down one fret (so the bar is on the 2nd fret and the other fingers on 3rd and 4th frets)

In music, there is NO (E#/Fb) and (B#/Cb)