I was 13 when I first got the itch to start a band. It was the early 90's and I was a teenager in Seattle-- the Grunge capitol of the universe. I was mesmerized by MTV and bands like Soundgarden and Nirvana were the coolest people in my world.
I couldn't play an instrument yet, but I was ready to start a band.
It was a few years later before I actually assembled my first band, but I had been planning it all along. Our name, logo, album tiles, style, attitude-- I had been crafting and changing that on notebooks and binder covers all through junior high.
Nevertheless, putting a band together doesn't happen out of thin air. It takes some thought and planning. Here's a neat article that gives some good pointers that can get you going in the right direction.
"Learn How to Find Musicians and Start a Band" by Heather McDonald