#1
i dont really know where is goes, but i just started learning guitar(i bought a guitar yesterday) and i am really confused on chords its not the finger placement that confuses me(sometimes it does) but im confused on what strings to strum. My friend told me to strum all of the strings and then another said only to strum the strings your holding, could someone please shed a new light on chords for me.
#2
each chord is different therfore require different strings to be strung, some require all six while others dont

i cant really explain how u can tell which needs the strings but download a trial version of Guitar Pro, and this can help out a bit,
#3
it's all in the name e.g. a chord
e-0
b-2
g-2
d-2
a-0
e-x
you don't play the low e it's muted with your tumb
as you can see the root of the chord is an A note. it's basicly like that with all chords.
try plucking every string starting from the low e and then from the A . hear the difference?
it's sounds better starting from a . try it with a d

e-2
b-3
g-2
d-0
a-x
e-x
it's the same idea the name of the chord determines the start
you might have trouble not hitting or muting the notes wich aren't part of the chord, but you'll learn it