If you want a simple, basic music program, I’d go for a cheap one by the name of FL studio mobile. It’s really really easy to learn and approach, and you can take your music with you wherever you go which is really nice. It’s only $14, but I’ve gained 2 front pages with it. If you’re into scoring, you can use the free program known as musescore, I’ve just made arguably one of my best pieces ever on it (warbird).