make piano keyboard on MacBook pro

You can show a virtual keyboard in GarageBand with the command "Window > Show Musical Typing ⌘K".

Or type the key combination ⌘K. This will open the Musical Typing window and you can use the keys of the Mac's keyboard to play music.

Just hit the keys A, S, D etc., that are displayed on the Musical Typing keyboard.

Buy a keyboard and connect by USB it will give you access to a grand piano, electric and an unbelievable assortment of instruments.So instead of using the built-in keyboard or keys. I have an 88 key and an Akai MPK Mini with a drum machine and 25 key.