Im working on a character in unity on a $2$D project that involves a character moving with W A S D and it needs to work around the vectors but I've ran into errors in my code. Below is my code what is the issue.

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class NewBehaviourScript : MonoBehaviour

$\{$

const float speed $=1\mathrm{.}0$f;

Vector$2$ velocity;

$//$ Start is called before the first frame update

void Start$()$

$\{$

velocity $=$ speed $*$ new Vector$2(1\mathrm{.}0$f$,0\mathrm{.}0$f$)$;

$\}$

$//$ Update is called once per frame

void Update$()$

$\{$

Debug.Log$("$Hi$")$;

if $($Input$.$GetKey$("$w$"))$

$\{$

velocity $=-1*$ velocity;

$\}$

transform.position $=$ transform.position $+($velocity $*$ Time.deltaTime$)$;

$\}$

$\}$