The next chord we’ll learn is the A Minor 7.
The seventh note being played in this chord is the same as the seventh note in the A Major 7, that is the open third string between your first and third fingers (G).
Take some time practicing this chord and then practice switching between A Major 7 and A Minor 7. After you can do this well, continue alternating between all the chords you have learned so far, calling out their names as you do so. Then practice doing so with some arpeggios. The A Minor and A Minor 7 sound great with arpeggios.