Not wanting to be too regimental but an acoustic piece normally requires at least 15 different finger positions. And I'm talking about a piece that's slightly more than 2 minutes.
You'll also want to rethink your right-hand style of playing. Losing the pick and going fingerstyle will open up lots of options for you in terms of how you play a chord. With fingerstyle, you have the option of plucking all strings simultaneously, strumming, and arpeggios. And there are variations for doing each of the three - again opening up lots of choices for you and immediately adding more dynamics to your playing.
Always listen to the best out there. Anything less means that you are shortchanging yourself - not a good thing.
In the 80s, lots of good rock and progressive guitarists had one acoustic piece within an album. Sad to say, that practice has died out these since.
Charlie Christian, Django Reinhart - both for soloing. Eventhough it's old jazz, it'll open your mind up to the way guitar soloing started on an acoustic instrument and the wonders of chord progressions.
Monte Montgomerry is awesomeness personified! Tommy Emmaneul is pretty good. Chet Atkins, Steve Howe, Flamenco guitarists are also a good listen.
There was a thread on songwriting, where RoRK shared what I think are good tips. Perhaps a look there might be good for you too. Essentially, be a good listener before you write your own stuff. And if you feel a need to write then do so but continue to lsiten to good stuff.
Your better stuff will come later rather than early. So starting early doesn't hurt at all. What you eventually come up with in your first few songs may eventually be broken up into parts for other songs, later on, as you develop your playing techniques and songwriting skills.
Good Luck and Have Fun!
Back then I was more into becoming a session player, or a guitarist in a band.