Thank me later
This is good... however if possible, ALWAYS try and learn on your own material, even if its trash.. this way you gain so much more fundamentals for the instruments your working with that can then really help later on.
Record small parts (not songs) - riffs/beats/whatever ya want. and then mix them 5 different ways.
before you can mix well, you need to really discover the instruments, how they live in the music, what's there evolvement, there tonal palate what's important about said instrument etc.