to use the 2D movement you need to make a script you can name the script whatever you want

use the namespace BEs.Tutorials.Movement._2D on your script remove the MonoBehaviour and replace it with PlayerMovement

and then you must write

using BEs.Tutorials.Movement._2D;

        public class YourScriptName : PlayerMovement
        {
            void Update()
            {
                movement();    
                WallJump(); 
                //movement is so the player can move, jump...
                //wallJump is so the player can walljump 
                //need to fix walljumping
            }
        }