I would suggest that you start by learning what the keys are. Then learn the basic scales, then learn how to form the basic chords. Also learn what the chords sound like. Gospel is probably the easiest style to learn in its most basic form. Learn a few basic songs that have the progressions that are common to church music. 90% of gospel artist use the same progressions and structure. It is not like they are fusion or jazz improvisers. Start at the basics. You don't need to learn to read if you are not going to play classical music. Not that it is bad, but for commercial music, from Gospel/R&B/pop/rock/hip hop, there is not too much to it. You can learn what progressions and chords and scales sound like and be on your way. No offense to sight reading, but sight reading does not teach you how to play an instrument. It can help you learn tunes, but most classical musician (90% and more) can master songs after they learn them from sight reading. Take the paper away and tell them to just play, and you will not get nothing out of them. Just do what I said and you will be fine.