Movement.cs

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

public class Movement : MonoBehaviour
{
    public Rigidbody2D myRigidbody;
    public Animator animator;
    public float moveSpeed;

    private Vector2 movement;

    // Dash variables
    private float activeMoveSpeed;
    public float dashSpeed;

    public float dashLength = .5f, dashCooldown = 1f;

    private float dashCounter;
    private float dashCoolCounter;

    void Start()
    {
        activeMoveSpeed = moveSpeed;
    }

    void Update()
    {
        movement.x = Input.GetAxisRaw("Horizontal");
        movement.y = Input.GetAxisRaw("Vertical");

        animator.SetFloat("Move", movement.x);
        animator.SetFloat("Speed", movement.sqrMagnitude);

        if (Input.GetKeyDown(KeyCode.C))
        {
            if (dashCoolCounter <= 0 && dashCounter <= 0)
            {
                activeMoveSpeed = dashSpeed;
                dashCounter = dashLength;
            }
        }

        if (dashCounter > 0)
        {
            dashCounter -= Time.deltaTime;

            if (dashCounter <= 0)
            {
                activeMoveSpeed = moveSpeed;
                dashCoolCounter = dashCooldown;
            }
        }

        if (dashCoolCounter > 0)
        {
            dashCoolCounter -= Time.deltaTime;
        }
    }

    private void FixedUpdate()
    {
        myRigidbody.MovePosition(myRigidbody.position + movement * activeMoveSpeed * Time.fixedDeltaTime);
    }
}