Start small, and start slow, and let the muscles get accustomed to the movement. There are piano music books for adult learners. Practice those pieces you like so you can stand to play them multiple times and listen to them that often.

Scales are good for warm-up, but they get boring if you play them long. Do you consider yourself knowledgeable regarding music theory? Do you read music? These things will influence how quickly you learn the instrument.

SRS