Hello there. Here are some humble suggestions to the questions you asked:
The only way to improve your ear is to listen to music. Listen to as much gospel music as you can get your "ears" on. Listen to music. Listen. Then listen to some more music.
Then print out some fully chorded songs and play them. Get used to the progressions, the sound of sevenths, the sound of diminshed chords, passing chords, etc. Pick out songs that you know, of course . . . that way you can associate chords with sounds.
For practice, it depends on where you are. Do you know all of the scales in every key? If not, then that is where you should begin. If you know the scales in every key, then you will want to learn the blues scale in every key.
Spend about fiteen to twenty minutes playing different progressions . . . 2-5-1, 7-3-6-2-5-1, 1-4-5 in your favorite keys.
Then play 2 songs that you know in 2 different keys, and 2 then songs that you are trying to learn in one key. Soon, when you know them in one key, then move them to the "songs you will practice in two different keys"
Hope this helps
BBoy
