Unity score raising question

You are about to write a code to keep score. There are several controls, so we split the code. In the event of a collision

scoreSum man = GameObject.Find("scoreManager").GetComponent <scoreSum>();
man.score ++;

I used to increase the score, and in the code scoreSum, I defined the text Sc and

void Start()

{

        score = 0;


}

void Update () 

{

        Sc.text = score.ToString();
}

This is how you continue to display your scores. However, the score is not initialized, and even if the score does not go up during the game, the score will not be displayed at once until the game is over and back to the game window. How should I fix it?