error CS1519 (invalid token ";") and CS1001 (identifier expected). Vector 3 problem (Brakeys Multiplayer tutorial ep 2)

The script in the video originally had a plethora of errors, and I’ve tried my best to fix the code and reduce the errors to as few as possible

The errors in my current script are:
Assets\PlayerMotor.cs(9,14): error CS1519: Invalid token ‘=’ in class, struct, or interface member declaration

Assets\PlayerMotor.cs(9,32): error CS1001: Identifier expected

My script is:

using UnityEngine;

[RequireComponent(typeof(Rigidbody))]

public class PlayerMotor : MonoBehaviour
{
    
    private Vector3 velocity;
    velocity = new Vector3(zero);

    private Rigidbody rb;

    void Start() 
    {

        rb = GetComponent<Rigidbody>();

    }

    //Gets a movement vector
    public void Move (Vector3 _velocity) 
    {

        velocity = _velocity;
        

    }

    //Run every physics iteration
    void FixedUpdate ()
    {

        PerformMovement();

    }

    //Perfrom movement based on velocity variable
    void PerformMovement() 
    {

        if (velocity != Vector3.zero){
            rb.MovePosition(rb.position + velocity * Time.fixedDeltaTime);
        }

    }
}

>Solution :

1. You can’t just write code inside class body like: velocity = new Vector3(zero);. What you can do, and what probably made you thought you could do that, is to initialize the variable at declaration: private Vector3 velocity = new Vector3(zero); Still, this has more issues.

2. Vector3 doesn’t have a constructor, that accepts only one parameter.

3. Even if it did, you would have to declare Vector3 zero as a static variable.

4. All in all, just use Vector3.zero where you need, there’s no point in declaring it yourself.