C语言未定义标识符及各种错误

问题遇到的现象和发生背景

VS2022下编译不通过，NULL显示的是未定义标识符，已经定义的结构体显示的是未定义标识符，各种错误都有

用代码块功能插入代码，请勿粘贴截图

#include <stdio.h>
#include <stdlib.h>


struct Node
{
    int data;
    struct Node* next; // C++中只需要写Node*
};
struct Node* head;
void Insert(int x)
{
    struct Node* temp = (Node*)malloc(sizeof(struct Node));
    temp->data = x;
    temp->next = head;
    head = temp;
}
void Print()
{
    struct Node* temp = head;
    printf("List is:");
    while (temp != NULL)
    {
        printf(" %d", temp->next);
        temp = temp->next;
    }
    printf("\n");
}
int main(void)
{
    int n, x;
    head = NULL;
    printf("How many numbers?\n");
    
    scanf("%d\n", &n);
    for (int i = 0; i < n; i++)
    {
        printf("Enter the number:\n");
        scanf("%d", &x);
        Insert(x);
        Print(x);
    }

    return 0;
}