Firstly you'll want to learn a bunch of theory. People say you should avoid theory as much as possible since it stifles the creative process to some degree, but these are the people who write entire albums in one key and that key is based on the note of the lowest string of their guitar. Learn about a thing called chord function. If you put specific chords in specific orders, it'll sound good. This explains it pretty well: https: //www.musictheory.net/lessons/57
A lot of the rest will depend on what type of music you want to play. One thing to keep in mind is that software instruments mostly sound like shit. It would be good to learn to play instruments and get some microphones and a recording interface. If you want to make electronic music then that doesn't matter.
If you're just concerned about writing it, you won't need to learn DAW stuff, but if you want to record it and mix it, let me just say now, it's going to sound amateurish unless you either pay a whole bunch of money and do some kind of university course or if you spend even longer scouring the internet for advice that isn't shit. If you don't want to have to pay someone else to record and mix your music, it's going to sound like it was put together amateurishly, but I doubt you're concerned about that. Again, how you record stuff depends on what kind of music you want to make. If you don't care about software instruments sounding like shit, you can just pirate some software, and there should be guides on the internet. You'll have to learn how to program midi. If you know enough about notes and rhythm, you can use a DAW or guitar tab software to input the notes you want it to play. A lot of this stuff in general depends on what kind of music you want to make so if your OP wasn't vague maybe it'd be easier to give advice. OP's probably not coming back anyway.