Building muscle takes a long time. Being that you're fourteen and have no sex hormones in you at the moment, you're pretty unlikely to wake up tomorrow looking like the incredible hulk. But until you start T, you can still get stronger!
A lot of strength is made not by adding muscle mass, but by developing explosiveness. And explosiveness is really just a fancy word for speed. Fast twitch muscles. There's that guy in Texas who can bend and fold metal pots & pans, but he's not very big. He just has incredibly explosive muscles and neurons.
Even after you start T, it still takes a long time to build muscle. Here, I recommend a site called Acrobolix. Since we're not allowed to post direct links on the forum, just do a search for Acrobolix. The guy who runs the site is an absolute sweetheart and will answer any questions you might have.