Hi Ryan. Well, there are only seven different notes in a scale, which work with seven different chords. In the key of C these would be C D E F G A B, which work with the chords C Dm Em F G Am Bm7b5 in any order you like. So armed with that concept, piano, guitar and bass are all just branches of the same tree. Learn the pattern on each instrument and you're there, at least at a basic level. This is all you need to start songwriting too. Good Luck.