Not to diss on PO. I was super hyped about it as well, and would have liked to know about its limitations before buying it. Anyone of the numerous phone apps would be a cheaper and better replacement for a PO.
What got me started in music was Garageband. It's free (for macos users) and quite simple and intuitive. It's not as fully-featured as something like Ableton, but quite capable for making professional-level songs.