I am making a fishing game where you can battle against each other online. but I dont know how to join a server and how to make a server please help.

this is my code till now:

pragma strict

 MasterServer.ipAddress = "127.0.0.1";
 
 var remoteIPadress = "192.168.0.13";
 var remotePort = "";
 var listenPort = "";
 
 var useNat = true;

 var myIP = "";
 var myPort = "";
 
 var MaxPlayers = 10;
 
 
 
 function Start () {
 
   //PlayerScript = GameObject.Find("spritenaorobot(Clone)").GetComponent(OnTriggerEnter);
 
 }
 function OnConnectedToServer()
     {
     
     Debug.Log("Server connect");
      GameObject.Find("Cube").transform.position.x = -5;   
     }
 
 function OnServerInitialized()
     {
         Debug.Log("Server Initializied");
         GameObject.Find("Cube").transform.position.x = 0;
     }
     
     
     function RefreshHostList()
     {                        //typename
     MasterServer.RequestHostList("Uniquegamename");
     
     }
     
 function OnGUI ()
 {//sort of Starting server
 
 if(Network.peerType == NetworkPeerType.Disconnected){}
 
 if(GUI.Button(Rect(5,5,80,30),"Connect")){
 
 Network.useNat = useNat;
 Network.Connect(remoteIPadress, remotePort);
 
 }
 if(GUI.Button(Rect(5,40,80,30),"Startserver")){
 
 
 Network.useNat = useNat;
 Network.InitializeServer(MaxPlayers, 25000);
 
 }
 
 remoteIPadress = GUI.TextField(Rect(5,100,120,30),remoteIPadress);
 
 
 }

i am 14 years old so it could be a dumb question.

greetings Paul PS:I am dutch so i could have made some mistakes in spelling.