How to start making music for my game?

Well, once my homebrew game is over. . . I need to add music, but I do not know music.

I'm using Famitracker to do some melody, but all I get is real crap.

Does anyone recommend any guidance or help?

The first step is coming up with a few good sounding instruments.

A good starting point is thinking about the properties, sounds and modes of playing a physical instrument, and then try to create a simplified abstraction of those properties.

The london philharmonic orchestra has a youtube series (and an interactive app) where you get introductions to each common instrument in an orchestra. The string ones are very basic introductions, but some of the other instruments go into sufficient detail.

Example:
https://www.youtube.com/watch?v=nENXs6n_ITI

Composing music takes practice, practice and practice. And theory. You'll come a long way getting comfortable with repeated combinations of the different note lengths (rythms) and practicing moving through the circle of fifths.

I think Drew Carey said this...how to write a joke...first, write 20 bad jokes. Then take the least bad joke, and rewrite it over and over until it's a good joke.

When I try to write a song, I will sit and goof around on the piano for an hour, until I have at least 1 line of decent melody, then I try to play 20+ variations on that melody, then I write it down (or record it), and spend weeks refining and refining until it's either a song, or (more often) a piece of crap that I toss in the garbage.

And, listen to good songs / look at good famitracker files. See how other people do it.

Unrelated...

Man 1-ask me, what's the most important thing about telling jokes.

Man 2-ok. What's the most important...

Man 1-Timing! (Interrupts)

What style of music are you trying to make?

One thing that I find that brings about creativity is to set limits onto yourself. And lucky for you, the 2A03 is severely limited.

Speaking of which, what kind of music engine are you using? Famitone? Will you be utilizing all four (or five) channels?

For what it's worth, I think my compositions (or whatever you call them) improved significantly after I did several classical/baroque NSF covers. So borrowing from classical music might help.

late 70s and 80s synth pop (especially depeche mode) may be a good case to study. It's outside original vgm music but still has limitations reminiscent of synth-on-a-chip melodies, for natural reasons.

Multitimbrality for melodies and bass are often low, sometimes 2 notes at a time, but there are still interesting melodic and rythmic movements to be found.