Okay, let's start by creating the new script to control the camera. 
With the Main Camera GameObject selected in the Hierarchy, select Add Component In the Inspector. 
Call your new script, CameraController. 
If you use the Inspector to create the script, it will be placed in the root or top level of the project folders. 
Move it to your scripts Folder. 
Open the new script for editing. 
This script needs two variables. 
A public GameObject reference to the player GameObject. 
And a private Vector3 variable to hold the offset value. 
Inside the first curly brace, add the following line. public GameObject player; 
This will reference the player GameObject's position. 
On a new line underneath, add another variable declaration. private Vector3 offset; 
This will store the offset value. 
The offset value variable is private because you're going to set the value in the script. 
Now that you've declared the variable, let's calculate it. 
To do this, you're going to take the current transform position of the camera GameObject and subtract the transform position of the player GameObject to find the difference between the two. 
The Start function is the best place for this code. 
It needs to be calculated immediately when the game starts, but it only needs to be calculated once. 
In the Start function, on a new line, after the first curly brace, let's write the equation like this. offset = transform.position minus player.transform.position; 
This will set off set equal to the camera transform position minus the player GameObjects transform position. 
Next, you're going to use that to set the camera GameObjects transform position. 
This needs to happen in every frame. 
So the best place for that code is the Update function. 
Inside the first curly brace, write transform.position equals player.transform.position + offset; 
Now when a player moves the sphere with controls on the keyboard, the frame before displaying the camera, the camera GameObject is moved into a new position, aligned with the player GameObject before the frame is displayed. 
This is just like what would happen if it were a child of that object, except it's only matching the position and not the rotation of the sphere. 
However, Update is not actually the best place for this code. 
It is true that Update runs every frame and in Update, each frame, you can track the position of the player GameObject and set the position of the camera. 
However, you don't control which order all of the Update functions happen. 
That means that the Update could run before other scripts or Unity systems that will change the player position, like the physics system. 
So, what's the solution? 
Well, for follow cameras and tasks, like gathering last known states, it's best to use Late Update. 
Late Update runs every frame just like Update, but will run after all of the other updates are done. 
Add Late in front of the Update method to change this. 
Okay, brilliant. 
Now, you know that the camera position won't be set until the player has moved for that frame. 
Let's save the script and return to Unity to test it out.