How to add force or velocity to the rigid body?

Questions & Answers
1

using UnityEngine;
using System.Collections;

public class PlayerShoot : Photon.MonoBehaviour {

public GameObject bulletPrefab;
public Transform muzzle;
// Use this for initialization
void Start ()
{
	muzzle = transform.Find("ShootSpot");
}

// Update is called once per frame
void Update ()
{
    
    if (Input.GetButtonDown("Fire1"))
    {
            SpawnMyMissle();
	}
}

void SpawnMyMissle()
{
	
	PhotonNetwork.Instantiate("MissleLaserMech", muzzle.position, muzzle.rotation, 0, null);
	//gameObject("MissleLaserMech").rigidbody.AddForce(-transform.forward * 10000);
    //The last argument is an optional group number, feel free to ignore it for now.
}

}

2

Use RigidBody.AddForce and/or RigidBody.velocity. Read the docs for details. Note that AddForce is meant to be used in FixedUpdate, and velocity for one-offs.

Which is best will be a decision you’ll have to make after trying both so see which feels best for your game.