What guitar chords should i learn next?
Work on the rest of the sharp and flat chords in major, minor and 7th. For scales, start with the major scale and then move on to minor and pentatonic. Once you have mastered these, take a look at modes. There are six of these: Dorian, Phrygian, Lydian, Mixolydian, Aeolian, and Locrian. They are much more interesting than the straightforward scales but you need to learn the other scales first in order to properly understand modes.