How to make a basic 2d movement script for a 3d game

hello,i was making a 3d game but the character in the game is a 2d sprite and i want the sprite to have a 2d left to right walk and a jump movement script on it and the script that i put on my sprite dosent work to well because it has rigidbody and when an object has rigidbody body is needs a collider or else its gonna fall through other object so when i put a collider on my sprite it dosent go on my sprite to well and the sprite cant walk right how can i make it to where i don’t need rigidbody for my sprite to walk and how can i add a jump movement to my script.

using UnityEngine;
using System.Collections;

public class movement : MonoBehaviour {

	public float speed;
	
	void Awake () {
		
	}
	
	void FixedUpdate () {
		
		if (Input.GetKey("a")) {
			GetComponent<Rigidbody>().AddForce (-Vector3.right * speed * Time.deltaTime);
		}
		if (Input.GetKey("d")) {
			GetComponent<Rigidbody>().AddForce (Vector3.right * speed * Time.deltaTime);
		}
	}
}
  1. You need to replace the Rigidbody with Rigidbody 2D in your script.
  2. Replace the Rigid body component in your inspector with Rigidbody2D.