Hey Joey, as far as ear training, start by being able to distinguish between and identify Major and Minor. Be able to tell whether the scale is major or minor and whether the chord is major or minor. In addition to that, start practicing your major scales while singing or humming the same note you play. This builds a connection between your ear and your fingers more than anything. You'll get better at locating which notes and intervals you're hearing in the melodies.
Also, as far as the cord techniques you might use..... Even a very straight forward and basic 3 chord song can me made very interesting by using embellishments and interesting rhythms. I like to use triad material and double stops or suspensions in my rhythm playing to make things a little more interesting. For me, I kinda think of it as the "Hendrix" _style_ of playing rhythm, but it comes from piano as well. Use your 2nds, 4ths, 6ths and approach notes to help make your chord work unique and interesting.
I'll also recommend a free ear training site, www.musictheory.net . Look for the scale and interval ear trainers, they're well designed, easy to use and free! Have fun!