how do i make something be controlled by the player?

First-off, make sure you've at least tried the provided tutorials.

I recommend starting with:

http://unity3d.com/support/documentation/Manual/Unity%20Basics.html

Then jumping to a more advanced tutorial like the 3D platform Game one:

http://unity3d.com/support/resources/tutorials/3d-platform-game

Alternatively you could search for the TornadoTwins channel on youtube although some stuff is a bit outdated in their tutorials. If you've exhausted all of these and you're still unsure about what to do next, ask google nicely, like:

http://www.google.com/search?q=unity3d+tutorials

you could use input. and say

if(Input.GetKeyDown("KeyNameAccordingToReference"))
    {}

reference can help you.

another input it doesn't tell you is

Input.mousePosition

which is where on the camera the mouse is (in a Vector3)

i recommend the tornado twins tutorials.