I would recommend getting hearandplay’s organ DVD series. It teaches praise progressions and worship progressions. I personally benefitted a lot from the worship dvds. It teaches you chords to play on every note of the major scale and this technique was super helpful for me to play songs and progressions in other keys (I don’t know of any other DVD’s that use this approach for organ - if there is let me know!). The organ is a beast instrument but keep praying, practicing, listening, and living a saved life and watch God use you!