How would I set up this blend tree for my 2d game

Hey im making a top down 2d game and im trying to set up a blend tree. The animations are walking up, left,right, and down. That means speed would not work. I dont know what would work so any help?

Heres my code

 using UnityEngine;
 using System.Collections;
 
 public class topdown : MonoBehaviour
 {
 
     public float moveSpeed;
 
     private Animator anim;
 
     public float velocity;
 
     public float Direction;
 
     public float x_move;
     public float y_move;
     public float input_x;
 
     public float input_y;
 
 
 
     public float speed;
 
     // Use this for initialization
     void Start()
     {
         anim = GetComponent<Animator>();
 
 
     }
 
     // Update is called once per frame
     void Update()
     {
         if (Input.GetAxisRaw("Horizontal") > 0.5f || Input.GetAxisRaw("Horizontal") < 0.5f)
 
         {
             transform.Translate(new Vector3(Input.GetAxisRaw("Horizontal") * moveSpeed * Time.deltaTime, 0f, 0f));
         }
 
         if (Input.GetAxisRaw("Vertical") > 0.5f || Input.GetAxisRaw("Vertical") < 0.5f)
         {
             transform.Translate(new Vector3(0f, Input.GetAxisRaw("Vertical") * moveSpeed * Time.deltaTime, 0f));
         }
 
         {
             if (Input.GetKeyDown(KeyCode.W))
                 anim.SetTrigger("Moving");
             if (Input.GetKeyDown(KeyCode.A))
                 anim.SetTrigger("Moving");
             if (Input.GetKeyDown(KeyCode.S))
                 anim.SetTrigger("Moving");
             if (Input.GetKeyDown(KeyCode.D))
                 anim.SetTrigger("Moving");
 
         }
         float velocity = Mathf.Abs(new Vector2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical")).magnitude);
         anim.SetFloat("speed", velocity);
 
         float curDirection = anim.GetFloat("Direction");
         {
 
         }
     }
 }