An couple of ideas:

Don't discount the ukelele as an instrument. It's much easier to learn to play than a guitar. I learned in elementary school. It can handle all the basic chords for campfire songs. A decent instrument should really have geared tuning heads. Ukes are a total hoot to mess around with!

For those who have an old guitar but don't play: you can still make pretty noises. Instead of standard tuning, drop both the high E (1st string, at the bottom) and the low E (6th string, at the top) down one full note to D. It now has a nice chord when you strum it open. And then you play an "A" chord and just move it up and down the neck (same fingering as A) until you find other spots that make nice chords. This works!

Don't have a guitar tuner? You can get them on your smartphone.