guitar help

 Here's the A Chord. It's played: open on the 1st string, 2nd fret on the 2nd string, 2nd fret on the 3rd string, 2nd fret on the 4th string, open on the 5th, and either mute or don't strum the 6th string.

 Now you got the A7 chord. It plays: open on the 1st string, 2nd fret on the 2nd string, open on the 3rd string, 2nd fret on the 4th string, open on the 5th string, and either mute or don't play the sixth string.

 Here's B. It's played: open on the 1st string, 4th fret on the 2nd string, 4th fret on the 3rd string, 4th fret on the 4th string, 2nd fret on the 5th string, and either mute or don't play the sixth string.

 So, here are some of the basic chords.

Here's C. It's played: 1st fret on the 2nd string, open 3rd string, 2nd fret on 4th string, and 3rd fret on 5th string.

 Here's your C7 chord. It's played: open on the 1st string, 1st fred on the second string, 3rd fred on the 3rd string, 2nd fret on the 4th string, and 3rd fret on 5th string. Either mute or don't play the 6th string.

 Here's D. It's played: 2nd fret on the 1st string, 3rd fret on the 2nd string, 2nd fret on the 3rd string, open on the 4th string, and either mute or don't play the 5th and 6th strings.

Here's D7. It's played: 2nd fret on the 1st string, 1st fret on the 2nd string, 2nd fret on the 3rd string, open on the 4th string, and either mute or don't play the 6th string.

 This is E. It's played: open on the 1st string, open on the 2nd string, 1st fret on the 3rd string, 2nd fret on the 4th string, 2nd fret on the 5th string, and open on the 6th string.

 This is E7. It's played: Open on the 1st string, open on the 2nd string, 1st fret on the 3rd string, open on the 4th string, 2nd fret on the 5th string, and open on the 6th string.

 Here's F. It's strummed: 1st fret on the 1st string, 1st fret on the 2nd string, 2nd fret on the 3rd string, 3rd fret on the 4th string, and either mute or don't play the 5th and 6th strings.

This is G. It's strummed: 3rd fret on the 1st string, 3rd fret on the 2nd string, open on the 3rd string, open on the 4th string, 2nd fret on the 5th string, and 3rd fret on the 6th string. 

This is the G7 chord. It's played: 1st fret on the 1st string, muted 2nd string, open on the 3rd and 4th strings, 2nd fret on the 5th string, and 3rd fret on the 6th string.