If you are just start to work with Unity and looking for simple character controller to control player with keyboard and mouse on PC you've found what you need. There is no modules, libraries and so on. Just pure C#. Script will found Camera on its own. All you need it's Capsule (or some 3D character) and script below. And you don't need to thank us that everything here is running, jumping, looking under your feet, controlled by a mouse.