guitars

The most important part is to get a good start, so you don't give up as the first thing.

Learn to tune it. Download any free tuner app.

Learn a chord. I suggest G. From the thickest string and down it's the frets: 3 2 0 0 0 3

Learn a song. The absolutely simplest song is the nursery song "Are you sleeping(brother John)" aka "Frere Jacques", because it has only one chord and everyone knows the lyrics and melody. This is how: Hold the G chord and play the thick string, then strum, play the open D string, then strum. Sing along. Do it step by step until you've got it.

Congratulations. You can now play guitar.

It's no joke. The reason why you should learn this is to have an achievable goal. I spent most of my teens learning about music theory, composition and guitar techniques etc., but I couldn't sit down and play a single simple song. It wasn't until much later that I managed to break from all that and learned to pick up a guitar and perform something that could be regarded as music. Knowledge is good, but performance is everything.