How to get a character to move left and right in Unity 2D. code example

Example: How to get a character to move left and right in Unity 2D.

//C# Unity2D
//I wrote this and I'm quite new to Unity and C# so it could probobally be improved.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class enemymovement : MonoBehaviour
{
	private float ogpos; //Original Position of the enemy
	public int distance; //How far we want to move in each direction
	private bool going; //Says if we are going left or right
	private float npos; //Our negative destination
	private float ppos; //Our positive destination
	private Rigidbody2D rb; //RigidBody2D

    void Start()
    {
    	going=true;
    	rb=GetComponent(); //RigidBody2D
        ogpos=transform.position.x; //We do this to get the position it started in. This is only the x along with ppos and npos
        npos=ogpos-distance; //Subtract from ogpos for the positive destination
        ppos=ogpos+distance; //Add to ogpos for positive destination
    }

    void Update()
    {
    	//Check if we are going right or left, true being right.
    	if(going==true){
    		rb.velocity = new Vector2(1,rb.velocity.y); // Add to go right The 1 is the speed
    		//Check if it's equal to or greater than our positive destination
    		if(transform.position.x>=ppos){
    			going=false; //Swap going
    		}
    	}
    	if(going==false){
    		rb.velocity = new Vector2(-1,rb.velocity.y); //Subtract to go left
    		//Check if it's equal to or less than our negative destination
    		if(transform.position.x<=npos){
    			going=true; //Swap going the negative one is its speed so if it was a variable multiply by negative 1
    		}
    	}
    }
}