Thats really it, but the advice I can give is how you go about learning that stuff and what you put time into.
I highly recommend transcribing and playing songs you like. Learn a new song every day even. When I say transcribe I don’t mean with a pencil and sheet music (though you could if you’d like) I just mean figure the melody out on your instrument of choice, play it, absorb it, sing it, internalize it, and when you do this day in and day out it becomes a part of you and will naturally come out in your music. It’s like a bank.
This same process can be used for harmony and structure–I. E. learning an entire song front to back and knowing why things are the way they are.
David Lee Roth was just on Joe Rogan and he said some really great things. When asked how long it took him to write Running With the Devil his response was basically “Well after about 500 books, thousands of hours of playing songs, 1000 movies… It took about 18 minutes to write”
There is no shortcut. If you hear a melody you like, learn the crap out of it and then analyze WHY you like it. “Oh that’s nice, it starts on a non chord tone and resolves to a chord tone, maybe I should do that” (that’s called an appogiatura btw)
“Oh the shape of that melody is so nice, it’s like an arch” (see: Paul McCartney melodies such as Yesterday, Fool on the Hill, Hey Jude, on and on)
Then as you do this you’ll find your note selection improving. You’ll go from lame, kinda square/cheesy notes to hip, happening notes. I’m learning blues piano right now and have recently developed an appreciation for blues note selection… It can just be so, so hip.