Press P to Pause unity c#

using UnityEngine;
using System.Collections;

public class Pauser : MonoBehaviour {
private bool paused = false;

// Update is called once per frame
void Update () {
if(Input.GetKeyUp(KeyCode.P))
{
paused = !paused;
}

if(paused)
Time.timeScale = 0;
else
Time.timeScale = 1;
}
}

1. Create one empty game object.

2. Attach script component to that game object.

3. Copy and paste above code on that script.

4. Play & Cheack

Camera follow the character unity 2D using c#

using UnityEngine;
using System.Collections;

public class CameraFollow : MonoBehaviour
{
public float xMargin = 1f; // Distance in the x axis the player can move before the camera follows.
public float yMargin = 1f; // Distance in the y axis the player can move before the camera follows.
public float xSmooth = 8f; // How smoothly the camera catches up with it's target movement in the x axis.
public float ySmooth = 8f; // How smoothly the camera catches up with it's target movement in the y axis.
public Vector2 maxXAndY; // The maximum x and y coordinates the camera can have.
public Vector2 minXAndY; // The minimum x and y coordinates the camera can have.


private Transform player; // Reference to the player's transform.


void Awake ()
{
// Setting up the reference.
player = GameObject.FindGameObjectWithTag("Player").transform;
}


bool CheckXMargin()
{
// Returns true if the distance between the camera and the player in the x axis is greater than the x margin.
return Mathf.Abs(transform.position.x - player.position.x) > xMargin;
}


bool CheckYMargin()
{
// Returns true if the distance between the camera and the player in the y axis is greater than the y margin.
return Mathf.Abs(transform.position.y - player.position.y) > yMargin;
}


void FixedUpdate ()
{
TrackPlayer();
}


void TrackPlayer ()
{
// By default the target x and y coordinates of the camera are it's current x and y coordinates.
float targetX = transform.position.x;
float targetY = transform.position.y;

// If the player has moved beyond the x margin...
if(CheckXMargin())
// ... the target x coordinate should be a Lerp between the camera's current x position and the player's current x position.
targetX = Mathf.Lerp(transform.position.x, player.position.x, xSmooth * Time.deltaTime);

// If the player has moved beyond the y margin...
if(CheckYMargin())
// ... the target y coordinate should be a Lerp between the camera's current y position and the player's current y position.
targetY = Mathf.Lerp(transform.position.y, player.position.y, ySmooth * Time.deltaTime);

// The target x and y coordinates should not be larger than the maximum or smaller than the minimum.
targetX = Mathf.Clamp(targetX, minXAndY.x, maxXAndY.x);
targetY = Mathf.Clamp(targetY, minXAndY.y, maxXAndY.y);

// Set the camera's position to the target position with the same z component.
transform.position = new Vector3(targetX, targetY, transform.position.z);
}
}

1. Select MainCamera
2. Add Script Component (c#) to Inspector window.
3. copy and paste above script.
4. Insert below parameters ( shown in image) to script components.