Second learnng the I,IV,V7 chord patterns--this will save you a lot of trouble. I somehow took five years of piano lessons and yet failed to translate all my theory nonsense into "guitar speak" until I took a beginner guitar workshop somewhere, years later. Suddenly, life got a whole lot easier.

Additionally, I think the minors are usually the VI and sometimes II (i.e. F# minor and secondarily B minor in the key of A, A minor and secondarily D minor in the key of C, etc.)