what should i do after Alfred's Basic Adult Piano Course: Lesson Book, Level 3
I would have several suggestions. First of all, find a classical piece that you have heard that is a bit of a challenge for you. The teachers that helped me the most when I took lessons are the ones that challenged me beyond what I thought I could handle. Slowly work on that piece of music. Take it apart a couple of measures at a time. First work on your right hand only. Then, work on the left hand only. When you are successful, put hands together.
Second, work on your scales, two to three octaves at a time. Know the scales and key signatures until they are mastered. Also, make sure you are familiar with chords. Practice chord inversions until you can change hand positions automatically. The last suggestion I have is to try picking out songs from the radio that you love. Start with the melody, and then add the left hand. Plan to spend lots of time at the piano. Definitely find a piano teacher to help you. Do what you love and love what you do!