You would be a lot better off learning about why certain notes sound good together than trying to get an AI to do it for you. That way you might develop skills that are transferable to making other songs, and you will get better at it. You're having a hard time right now because you don't know why certain notes sound good together, you're just dragging notes around and hoping it starts to sound good.
Here are some quick links. I'm happy to help further if I'm able.
Basics of harmony: https://youtu.be/3tuQrKWLCKc
Common chord progressions: https://youtu.be/Vyc8lezaa9g
How to build a chord: https://youtu.be/__VtlxQZhXs
Parts of a song: https://youtu.be/UxyrXqBQEpE