How do I get all of my code in start function

I need to put all of my code in the start function but I am getting an error : CS1525 symbol private . When I put the code in the start function the error came up at the bottom. Here is my code :

 public class MyClock : MonoBehaviour
  {
      public int  Minutes = 0;
      public int  Seconds = 0;
  
      private Text    m_text;
      private float   m_leftTime;
  
      private void Start()
      {
          m_text = GetComponent<Text>();
          m_leftTime = GetInitialTime();
      if (m_leftTime > 0f)
          {
              //  Update countdown clock
              m_leftTime -= Time.deltaTime;
              Minutes = GetLeftMinutes();
              Seconds = GetLeftSeconds();
  
              //  Show current clock
              if (m_leftTime > 0f)
              {
                  m_text.text = "Time : " + Minutes + ":" + Seconds.ToString("00");
              }
              else
              {
                  //  The countdown clock has finished
                  m_text.text = "Time : 0:00";
              }
          }
      
  
      private float GetInitialTime()
      {
          return Minutes * 60f + Seconds;
      }
  
      private int GetLeftMinutes()
      {
          return Mathf.FloorToInt(m_leftTime / 60f);
      }
  
      private int GetLeftSeconds()
      {
          return Mathf.FloorToInt(m_leftTime % 60f);
      }
  }