Hmm... First learn the first seven basic chords A, B, C, D, E, F, G... Then play lots of songs based only on the same seven. When you can play at least three songs properly, move on to the minors, learn them and play songs based on the keys and their minors. Once you are done, start picking random songs to play and whichever key you come across, learn it and play it. If you need more help, PM me! God bles