Learn all the major and minor chords first. Then do some drills, start at the low e (top string) and pull it open then first fret, second fret, third fret, and forth fret. Move down to the next string and do the same until you are at the bottom. When you are at the bottom do the opposite. Go 4th 3rd 2nd 1st and open.
Try learning the intro to walk the line (first learn tabs, they're easy) http://www.azchords.com/c/cashjohnny-tabs-717/iwalkthelineeasy-tabs-69698.html
Find progressively more difficult songs to learn.