I want to Keep player moving in up direction as well as to move sideways by the user input. ,How can i keep the player moving upwards and sideways as well?

I am making a 2d game in which player moves forword by default and it is supposed to turn sideways as per user input following is the code I have written

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class playermovement : MonoBehaviour {

 public float Sidespeed = 10f;
 public float UpSpeed = 5f;
 public float mapwidth = 5f;
 private Rigidbody2D rb;
 float movement = 0.0f;
 // Use this for initialization

 void Start()
 {
     rb = GetComponent<Rigidbody2D>();
 }

 // Update is called once per frame
 void Update()
 {
     
     movement = Input.GetAxis("Horizontal") * Time.deltaTime * Sidespeed;
     Vector2 newpos = rb.position + Vector2.right * movement;
     newpos.x = Mathf.Clamp(newpos.x, -mapwidth, mapwidth);
     
     rb.MovePosition(newpos);
     
 }

 void FixedUpdate()
 {
     Vector2 velocity = rb.velocity;
     velocity.y = UpSpeed;
     rb.velocity = velocity;

 }

},I am trying to make a 2d game in which player is continuously moving upwards and I want him to move Side to side with the userinput. Following is the code I have written.

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class playermovement : MonoBehaviour {

 public float Sidespeed = 10f;
 public float UpSpeed = 5f;
 public float mapwidth = 5f;
 private Rigidbody2D rb;
 float movement = 0.0f;
 // Use this for initialization

 void Start()
 {
     rb = GetComponent<Rigidbody2D>();
 }

 // Update is called once per frame
 void Update()
 {
     
     movement = Input.GetAxis("Horizontal") * Time.deltaTime * Sidespeed;
     Vector2 newpos = rb.position + Vector2.right * movement;
     newpos.x = Mathf.Clamp(newpos.x, -mapwidth, mapwidth);
     
     rb.MovePosition(newpos);
     
 }

 void FixedUpdate()
 {
     Vector2 velocity = rb.velocity;
     velocity.y = UpSpeed;
     rb.velocity = velocity;

 }

}