Creating a Wall Jump (Absolutely new to C#)

So in following a bunch of tutorials on Youtube, I've finally been able to set up a character that I've mapped controls to, even a jump feature. But, now I'm trying to implement a sort of wall jump, but in my research, I've haven't the slightest clue what to add to my already established code to do so:

 using UnityEngine;
 using System.Collections;
 
 public class PlayerMove : MonoBehaviour
 {
     public CharacterController controller;
     public float Speed = 7f;
     public float gravity = -20f;
     public float jumpHeight = 3f;
     public Transform groundCheck;
     public float groundDistance = 0.4f;
     public LayerMask groundLayers;
 
     Vector3 velocity;
     bool IsGrounded;
 
     void Update()
     {
         IsGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundLayers);
 
         if (IsGrounded && velocity.y < 0)
         {
             velocity.y = -2f;
         }
 
         float x = Input.GetAxis("Horizontal");
         float z = Input.GetAxis("Vertical");
 
 
         Vector3 movement = transform.right * x + transform.forward * z;
         controller.Move(movement * Speed * Time.deltaTime);
         
         if (Input.GetButtonDown("Jump") && IsGrounded)
         {
             velocity.y = Mathf.Sqrt(jumpHeight * -2f * gravity);
             
         }
         velocity.y += gravity * Time.deltaTime;
         controller.Move(velocity * Time.deltaTime);
     }
 }