Simple Tut

The most simple tutorial:

Create a new project

Save the scene as "Main" in the Assets Directory

Create a cube, Rename is "Player"

Reset the "Player" transform

Change the "Player" transform.scale.z to 2

Create 2 scripts: Mover, Shooter, Open them for editing

Look up "Input.GetAxis" in the docs

Copy the contents of the "Update" function into the "Update" in your "Mover" script

Look up "Input.GetButton" in the docs

Copy the contents of the "Update" function into the "Update" in your "Shooter" script

Create a new sphere, Rename it "Shot"

Change the "Shot" transform.scale to (0.5, 0.5, 0.5

Drag the Sphere into the project view

Delete the Sphere from the scene (this makes a prefab of the Sphere)

Drag the Sphere Prefab into the "Projectile" slot on the "Player"s "Mover" script

Save

Play

Hold down the Arrow Keys or WASD keys to move, and the Left Mouse button to leave spheres behind