I am going to upgrade my membership tomorrow. I consider myself an advanced beginner. I can rotate through the"cowboy chords" comfortably, can play simple songs, like CCR, most punk, Nirvana easy stuff. Should I begin with the Core lessons, or something else? I hope to gain proficiency to play in church. My main love in musuc is jazz. Thanks! I have a Framus Stellara guitar, a hollow body electric, no amp yet.