Code editor doesnt work,My scripts dont work!

So i downloaded and used unity for the first time today, everything was working fine till i made a script, it opened visual studio by default, and i think i messed with when you open unity and click on the top right conrner under maximize, like a settings button. so i clicked there and messed with the "Unity editors folder" then i typed the method which goes like(you can find the code when u scroll down a bit) and the functions didnt offer autocomplete or anything of the sort, i thought my visual studio was not working fine so i just saved it and tried to run the game but when i clicked my Sprite it didnt change colors... Please how do i fix this?

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

public class Bird : MonoBehaviour { private void OnMouseDown() {

   GetComponent<SpriteRenderer>().color = Color.red;

 }

} }