それがそのエラー内容です↓
MissingComponentException: There is no 'Rigidbody2D' attached to the "orb_0" game object, but a script is trying to access it.
You probably need to add a Rigidbody2D to the game object "orb_0". Or your script needs to check if the component is attached before using it.
UnityEngine.Rigidbody2D.set_velocity (UnityEngine.Vector2 value) (at <3f2225e513de4b60b88ec99ae0afafc1>:0)
orbcontlloer.Start () (at Assets/orbcontlloer.cs:12)
調べてみましたがよくわかりません
構文↓
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class orbcontlloer : MonoBehaviour
{
private Rigidbody2D rb2d;
// Start is called before the first frame update
void Start()
{
rb2d = GetComponent<Rigidbody2D>();
rb2d.velocity = Vector3.left;
} // Update is called once per frame void Update() { }
}