If you can get to play all the following basic chords without touching the other unnecessary strings and holding the right strings firmly, you are good to go, you will be able to play almost any song on your guitar that you hear today. It might take a while to get it right, but if you keep practicing, your hands will develop the muscles that you require and with time you will be good to go
This is a video illustration to playing all the open chords below:
Firstly the numbering on the images signify the fingers used to play the notes.
1 is the pointer finger
2 is the middle finger
3 is the ring finger
4 is the pinky