multiplayer variable synchronization problem

Hello All, I am new to unity multiplayer and i am have a problem getting other player in network i want to get other player and enable or disable other players components or children.

I attached the code and in code i comment the requirments

please let me know if you did not get the answer Advance Thanks For The Help

 using System.Collections;
 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.Networking;
 
 public class ScoreManager : NetworkBehaviour
 {
     private static ScoreManager instance;
     public static ScoreManager Instance {
         get {
             return instance;
         }
     }
 
     [SyncVar]
     public int score;
     [SyncVar]
     public int grass = 1;
     [SyncVar]
     public bool failed;
     [SyncVar]
     public bool complete;
     public Text MyScoreText;
     public Text MyGrassText;
     public Text OppenentScoreText;
     public Text OppenentGrassText;
     public GameObject CompletePanel;
     public GameObject FailedPanel;
     public GameObject PlayPanel;
 
     void Awake ()
     {
         instance = this;
     }
 
     void Update ()
     {
         MyGrassText.text = grass.ToString ();
         MyScoreText.text = score.ToString ();
         //and other player grass text and score text
     }
 
     void OnTriggerEnter (Collider other)
     {
         if (other.gameObject.tag == "hurdle") {
             print ("GameOver....! :P");
             failed = true;
             //here i want to true other player complete = true;
             //and also want to call other player Check();
             Check ();
         }
         if (other.gameObject.tag == "Single") {
             print ("Single....! :P");
             score += 10 * grass;
         }
         if (other.gameObject.tag == "Double") {
             print ("Double....! :P");
             score += 20 * grass;
         }
         if (other.gameObject.tag == "Grass") {
             print ("Grass....! :P");
             grass++;
         }
     }
 
     void Check ()
     {
         if (complete) {
             CompletePanel.SetActive (true);
             PlayPanel.SetActive (true);
         }
         if (failed) {
             FailedPanel.SetActive (true);
             PlayPanel.SetActive (false);
         }
     }
 }