If you connect a musical keyboard (using USB or MIDI), Synthesia for macOS listens to your playing and helps you learn any song. It shows any MIDI song as falling notes or sheet music so you can follow along easily. The scoring and progression systems help keep track of personal growth on each piece. The program is also a nice companion tool for daily practice to complement piano lessons. It's a nice platform for quickly sight-reading a new piece, and nearly any song can be found in the MIDI format that Synthesia understands. The app is also great for more experienced players. Learn to Play the Piano From Scratch for FREE! Playing songs right away provides great motivation to stick with the piano where you can learn traditional sheet music notation over time as you go along, should you choose to.
You can get started immediately without knowing how to read sheet music. Synthesia lowers the barrier to entry for beginners.
Synthesia for Mac is a game that can help you learn how to play the piano using falling notes.